VW Passat Tdi Sport 130 2002 - Loss of Power - Turbo not kicking in

[iworld]

Can anyone please advise

I have a VW Passat TDi Sport 130 on a 2002 plate. The car had an intermittent power problem then the I lost power. I assumed the Air mass meter was at fault. I went to my local VW and had it replaced. Still nothing - it was still the same. I then took the old one back and got it replaced - and the second one did not work either. Frustrated i went to another dealership who just fittend the 3 pipe valve that sits between the turbo and air flow meter and still nothing! The garage told me it was something to do with my turbo -

If the turbo goes surely it should make a noise - i think its just a couple of pipes loose or a blockage somewhere - can anyone shed some light?

[Crasher]

Probably jammed turbo vanes but have you been informed of any fault codes? Surely one of these places must have read the ECU for codes?

[iworld]

Probably jammed turbo vanes but have you been informed of any fault codes? Surely one of these places must have read the ECU for codes?


Hi
Thanks for the reply. I will investigate this. I do not have the info on me regarding the fault code and the info given on the problem - i will post this later - what is jammed turbo vanes?

[iworld]

Hi
Thanks for the reply. I will investigate this. I do not have the info on me regarding the fault code and the info given on the problem - i will post this later - what is jammed turbo vanes?


Hi

I had the info on me after all! The info given to me by the VW garrage

was under there diagnostic:

Charge pressure
Control postion Deviation
Error code 17965

I do not know what they mean - but the car was fine - my dad was chjanging the fuel filter before the car lost power. He did say that there was a leak from the fuel filter as he installed the incoreect one - could diesal have gone anywhere near the pipes or the turbo itself?

[Crasher]

The two common reasons for this are jammed turbo vanes (Google "variable geometry turbo" for an explanation) and a jammed or occasionally a jamming MAP (Manifold Absolute Pressure) sensor. The MAP has to be diagnosed using a diagnostic computer whilst watching what are known as Measured Value blocks or live data. The sensor can be observed in Measuring blocks 08; sub group 011 in display zone 3 and the value should rise and fall with boost. What often happens is the value sticks at 2880 mBar and the ECU doesn’t like this so it shuts off the boost until the engine has been turned off and then back on. If the turbo vanes jam, most garages will try to sell you a new turbo or at least a strip down and clean. I have found that using the diagnostic computer in Basic settings 04, the vanes can be freed of with a light tap on the end of a long bar, directly onto the vane operating rod as the computer display changes from off the on. Also, a valve called an N75 can occasionally be responsible for this fault and this is checked in output tests. As you can see, this problem needs someone who knows the car and has the diagnostics system, to deal with it.

[iworld]

The two common reasons for this are jammed turbo vanes (Google "variable geometry turbo" for an explanation) and a jammed or occasionally a jamming MAP (Manifold Absolute Pressure) sensor. The MAP has to be diagnosed using a diagnostic computer whilst watching what are known as Measured Value blocks or live data. The sensor can be observed in Measuring blocks 08; sub group 011 in display zone 3 and the value should rise and fall with boost. What often happens is the value sticks at 2880 mBar and the ECU doesn’t like this so it shuts off the boost until the engine has been turned off and then back on. If the turbo vanes jam, most garages will try to sell you a new turbo or at least a strip down and clean. I have found that using the diagnostic computer in Basic settings 04, the vanes can be freed of with a light tap on the end of a long bar, directly onto the vane operating rod as the computer display changes from off the on. Also, a valve called an N75 can occasionally be responsible for this fault and this is checked in output tests. As you can see, this problem needs someone who knows the car and has the diagnostics system, to deal with it.

:Blush:Thank you once again for a comprehensive and detailed answer - i will certainly try the recommendations and feedback to you the results

Just out of interest if the temp gauge does not move - when it drives then comes on again - what could that be? The tmep guage is 90 - some times it goes and sometimes it just stays at 0

Thanks

[Crasher]

Faulty coolant temperature sender. This should have come up as a fault code but may only be affecting the instruments which will have a code stored. It is cheap but fiddly to replace.

[iworld]

:Blush:Thank you once again for a comprehensive and detailed answer - i will certainly try the recommendations and feedback to you the results

Just out of interest if the temp gauge does not move - when it drives then comes on again - what could that be? The tmep guage is 90 - some times it goes and sometimes it just stays at 0

Thanks


Hi

I had replaced the Air Mass MEter - then the AirVacum valve - still nothing has made an impact - what was interesting before i replaced the air vacum valauve was my mechanic used a spare one that he used - which was not the coreect one for the car - when i took it for a spin the turbo kicked in at over 2000rpm which is not ideal as it should kick in at 1700-1900rpm as the manual states. When i deduced the air vacum valuve as the problem - i took i purchased a new vacum valve from VW and had it installed from another VW garrage - (silly i know) sadly this had not rectified the problem. Does that mean i have to repalce the air vacum valve again adsthe new one may be faulty or incompatible? It really seems strnage as the error codes above only occured after i installed the new air vacum valve - they were not there before - the message i received before was for the air mass meter.

Can you advise?

thanks

iworld

[Crasher]

What fault codes are you getting now? It sounds like you have a faulty MAP sensor. Please don't take this personally but that last post wasn't at all easy to read.

[iworld]

Probably jammed turbo vanes but have you been informed of any fault codes? Surely one of these places must have read the ECU for codes?


Just the error code 17965 -so far that i know

[Crasher]

The VW explanation for that code is; 17965/P1557 Charge pressure control, Control limit exceeded. Possible reasons, Hose connections interchanged or not attached. Effect, charger pressure too high so reduced output. Check N75, check charge pressure control.

I have seen this many times on this model due to the Manifold Absolute Pressure (MAP) sensor sticking at an indicated 2880 mbar. This sensor is located on the boost pipe that runs across the back of the engine bay and is held in with two screws, either Phillips or Torx head. The sensor is available from VW under the part number 038 906 051 C and costs £34.72 inc. VAT from VW and takes minutes to fit. This part number is for a 2002 Passat with either an AVF or AWX engine. If the turbo vanes jam, they tend to have the same effect so really you need someone who knows how to use VAG-COM and Basic setting 04, sub group 011 to trigger the vane control actuator and measuring blocks 08, sub group 011 to observe the actual boost pressure in display zone 3. Using Basic settings 04, 011 it is often possible to free off jammed turbo vanes without resorting to removing the turbo.

[iworld]

The VW explanation for that code is; 17965/P1557 Charge pressure control, Control limit exceeded. Possible reasons, Hose connections interchanged or not attached. Effect, charger pressure too high so reduced output. Check N75, check charge pressure control.

I have seen this many times on this model due to the Manifold Absolute Pressure (MAP) sensor sticking at an indicated 2880 mbar. This sensor is located on the boost pipe that runs across the back of the engine bay and is held in with two screws, either Phillips or Torx head. The sensor is available from VW under the part number 038 906 051 C and costs £34.72 inc. VAT from VW and takes minutes to fit. This part number is for a 2002 Passat with either an AVF or AWX engine. If the turbo vanes jam, they tend to have the same effect so really you need someone who knows how to use VAG-COM and Basic setting 04, sub group 011 to trigger the vane control actuator and measuring blocks 08, sub group 011 to observe the actual boost pressure in display zone 3. Using Basic settings 04, 011 it is often possible to free off jammed turbo vanes without resorting to removing the turbo.


:Blush: Many thanks for the advise!

I will get this checked out with my mechanic!!!!

I noticed when i sat in the car today that the boost mysteriously came back on for a couple of minutes driving - then i lost boost pressure MMmmm
So the turbo definatley works - i will have to action your advice asap

Thanks again and 10/10 for your advice

[Jakes Dad]

I get the same problem with my Passat although my codes are slightly different ?

Fault Code ~ 17964 = charge pressure control - regulating limit not reached (sporadic fault)

If i drive it harshly up hill i dont get the problem but if i take it easy on the throttle the Turbo kicks out at about the 1800 rpm mark as its rising ... we have changed the M A P censor and all of the pipe work incase it was sucking in any air but to no avail so maybe it might be the turbo vanes jamming on mine too ? it always seems to be worse on a wet or damp day than a nice warm sunny day ?

Simon

[Crasher]

Yes, that is characteristic of jammed vanes. If yours is a PD, these can usually be freed off using VAG-COM and a gentle tap on the operating rod.

[iworld]

Yes, that is characteristic of jammed vanes. If yours is a PD, these can usually be freed off using VAG-COM and a gentle tap on the operating rod.


Hi

Sorry been away for a while - my mechanic has not had time to look at the car properly yet - he has reset the memory on the car and the symptoms are still the same - what is funny i keep getting intermittent powerloss - most of the time the car does not boost and then when it does it comes in one go
i.e if i rev the engine above 2000rpm the turbo kicks in and i go through the gears - it then drops off the same way it came on. Some people have said that the turbo needs replacing - but i know the turbo works - does anyone have a diagram or guide to find out where the turbo vanes are. Why does the turbo come on and off when it wants to - i really want to get to the bottom of this so when the problem is fixed - i can help others with a similari problem - replacing the turbo is a admitting defeat!

Any suggestions - would appreciate

[Crasher]

The vanes are inside the turbo. What were the fault codes your mechanic found?

[iworld]

The vanes are inside the turbo. What were the fault codes your mechanic found?

Hi Crasher!

The code that came up is 462D Boost Pressure Control above Upper Limit

& 17965 Turbo pressure control limit exceeded

He says my manifold pressure is too high reading at 2983! when it should be 1000

When he removed the MAP sensor it went down to 1000 when he placed it back on and left the engine running it went back up to 2983!

So i am going to chnage the MAP sensor - what i am worried about is that a VW guy said that i need a Turbo when i told him this - se says behind the turbo - the blades are not working - i may need to clean them - but a Turbo is likely! I dont buy that - i going to get that MAP sensor replaced - he says that if it does not work - it could be something with the wiring - he will reset the memory - i am hoping it will work!

Interesting note though is that Boost Pressure, nominal is 15 Psi
But the Boost pressure actual is 43! PSi When he removed the map or disconnected it it went to 14Psi - do you think that a new MAP sensor will work?


Also the airm ***, nominal is 250mg/s

And the Air mass actual is 671.0mg/s

Other error codes indicated 44A1Temperature sensor intake manifold open circuit/positive short

& 449C Intake manifold pressure sensor open circuit/earth short!

Thats all for now - would appreciate your thoughts on all this info and advice

regards
I am hoping ti will sove the problem

[Crasher]

17965 can be a faulty MAP sensor and 2983 mBar is the figure they give when they fail but it can also be sticking turbo vanes. Don't let someone push you straight into a new turbo, it is often possible to free them off using diagnostic equipment and if you do a search on this I have posted it about ten times in the last week, getting rather fed up of re-writing it time and time again so I might just do a guide to the job and point people in that direction each time.

[iworld]

17965 can be a faulty MAP sensor and 2983 mBar is the figure they give when they fail but it can also be sticking turbo vanes. Don't let someone push you straight into a new turbo, it is often possible to free them off using diagnostic equipment and if you do a search on this I have posted it about ten times in the last week, getting rather fed up of re-writing it time and time again so I might just do a guide to the job and point people in that direction each time.


Good news! Finally!

I replaced the MAP sensor and the cars turbo kicked into life!! It has been a rollercoaster - but i never gave up hope - Thanks to people like Crasher and all the techie guys out there who are on this forum helping people and providing them with best alternative!

The turbo vanes are not jammed - as they are moving freely

Thanks again!

[n793]

its defo MAP sensor

[nuttley]

Hi, i'm new to the forum, although i've used it before to sort the wonderful water in the footwell problem, thanks to everyone who contributes it must save lots of people a lot of cash!

Rather than starting a new thread on what seems to be a common turbo problem i thought i'd try here for a little more info. I have a 2001 130PD and the turbo is only coming in about 2.5k-3k rpm no black smoke or any other issue. I tried thrashing the knackers off it to see if it cleared anything but that just put it into limp mode, after hittting the red line a couple of times. So i figure it could well be the MAF or MAP sensor and want to try changing these first. I know where the MAF sensor is but could someone detail a little more where the MAP sensor is? I have this descption from another thread "MAP sensor is located on the boost pipe that runs across the back of the engine bay and is held in with two screws, either Phillips or Torx head" is it easy to get to or obvious to see? i dont know what i'm looking for and cant find a photo on here, if someone has the part numbers for these or where i should look for them it would be really appreciated.

[Crasher]

I think you should have a fault code read done first.

[nuttley]

Thanks for that, i think your probably right about the code, it makes sense judging byt the cost others have metnioned. Will be on to my local VW garage in the morning, cheers

[nuttley]

So i had the fault codes read at my local independant garage and it was showing

17965 P1557
Turbo Sporadic:super charger overboost
condition:control limit exceeded.

The car was then taken for an 8 mile trip and re read with no fault codes coming back.

Am I right in assuming this is likely to be the MAP or the vanes sticking?

The garage said the possible causes were 1.Hose connection interchange/not connected 2.TC Boost pressure sensor 3. TC waste gate regulating valve

[Crasher]

Usually sticking vanes but can be the MAP sensor. The explanations they gave you were the ones listed by VAG which don't take into account defects VAG didn't expect. If it was the MAP sensor (VAG call it a Thrust Sensor) it would more than likely have re-occurred very quickly on a road test but sticking vanes don't always register quickly.

[nuttley]

thanks for the info. i went out and got a MAP sensor this lunch time given the cost is low and i cant get the car into the garage for a week. The garage told me they know of someone they use that has a machine for flushing turbos (i think that was how they said it) ever heard of these? know if they are worthwile and likely to clear sticky veins?

Going to change the MAP tonight and will post up if it makes any difference.

[Crasher]

I have heard off it but not had experience of it.

[nuttley]

well changing the MAP seems to have done the job. The turbo now kicks in as it should, although i'm not convinced its as powerful as it should be and after reading some of the mpg threads its not as good as it should be. I could see gunk in the pipe the MAP is attached to, is that normal? I guess its worth cleaning the pipes out either way. I noticed that where the pipe connects to the other pipe (excuse my poor descriptions) heading towards the front of the engine bay there was some oil, and it is clearly coming from around the join.

[Crasher]

A little oil in the charge pressure pipes is normal.

[wizard786]

The VW explanation for that code is; 17965/P1557 Charge pressure control, Control limit exceeded. Possible reasons, Hose connections interchanged or not attached. Effect, charger pressure too high so reduced output. Check N75, check charge pressure control.

I have seen this many times on this model due to the Manifold Absolute Pressure (MAP) sensor sticking at an indicated 2880 mbar. This sensor is located on the boost pipe that runs across the back of the engine bay and is held in with two screws, either Phillips or Torx head. The sensor is available from VW under the part number 038 906 051 C and costs £34.72 inc. VAT from VW and takes minutes to fit. This part number is for a 2002 Passat with either an AVF or AWX engine. If the turbo vanes jam, they tend to have the same effect so really you need someone who knows how to use VAG-COM and Basic setting 04, sub group 011 to trigger the vane control actuator and measuring blocks 08, sub group 011 to observe the actual boost pressure in display zone 3. Using Basic settings 04, 011 it is often possible to free off jammed turbo vanes without resorting to removing the turbo.




hi crasher i have a power loss problem and have vag com was wondering if you could be a bit more clear on section you have to go to to look at readings am pretty sure its either my map sensor or N75 but i dont want to waste money on guessing if you want to mail me direct you can on shazad.manzoor@orange.net as i cant always get on tyre smoke.

[Crasher]

TYRE SMOKE!!!! Anyway, what is your car?

[matjill]

Hi all- great forum first post I have a tiptronic alhambra tdi 115 with a AUY engine which was perfect before I loaned it to a family member for a few months. When I got it back it was horrible to drive.
It came back in Limp mode, a term I'd never heard of before as I am not a mechanic. I read a bit on these forum about this symptom and I was not prepared to take it to the dealers becouse of previous bad experience. Anyway cut along story short I first changed the air mass thing cost nearly £60 which made no difference. Then after more reading I felt that the turbo was to blame.I spent £460 on a recon turbo got a local mechanic to fit it in. Result still the same. It drive's upto 60mph then dies, foot down revs upto 4500 won,t stay in 5th drops down to 4th kick down totally useless going up hill. I begged a friend of mine to have the diagnostic test done and it came up with this fault code 17965 p1557. I have read all the post and will let you know what how things develop with the vacuum pipes and N75 Map etc, If that wasn't all the friend who diagnosed the fault code, wrecked the front window winder ( motor grinding the cable)! another £80 to find -

[Crasher]

Why didn't you have the fault code read done before fitting a new turbo? 17965 indicates an over boost situation which could be the MAP sensor, N75 valve, a vacuum pluming problem or even still a faulty turbo, I have seen a number of recon turbo’s still exhibit this fault. It needs someone who is experienced at these engines to spend some time with the diagnostic computer and do some tests in Measuring Blocks 08.

[Mike McKinstry]

Crasher,
When you say that vagcom and a hammer will usually free up the VNT in the turbo presumably this would only be if the fault was permanent .Otherwise would the vanes not stick again at the particular opening if the fault had been intermittent.Obviously it would be nice to think an intermittent fault with VNT could be cured with vagcom however surely cleaning would be the only permanent answer or am I wrong?

Regards,
Mike

[Crasher]

Yes, this is only for vanes that are stuck in one position which is quite common.

[matjill]

I wish I had taken it to the vag com to get the code now looking back- I was reading the wrong threads, all turbo related , they all advised turbo replacement, I only came across this thread by typing the fault code in google. I was so convinced it was the turbo, I thought I knew it all. As soon as I get it sorted will report back

[Mike McKinstry]

Thanks Crasher.

Mattjill as a matter of interest where did you buy your recon turbo and was price fitted etc or did you do yourself.

Mike

[matjill]

Thanks Crasher.

Mattjill as a matter of interest where did you buy your recon turbo and was price fitted etc or did you do yourself.

Mike
www.turbotechnics.com (http://www.turbotechnics.com) is where my turbo came from, Northampton.
they took mine in part exchange. No the fitting was done by local mechanic charge £125 about 6hr of work for him, stood and watched him take it out and fit it in, bit of struggle to take out. It came out from the bottom, only removed the exhaust front section to make some space and popped out.

[matjill]

Problem sorted on my alhambra! egr valve / inlet manifold blocked up with black sticky tar and a faulty n75 contol valve. cleaned and replaced. paid mechanic £150. Restored performance. window winder cable tangled up lucky motor was ok replaced mechanism cost £48 this I did myself quite easy. I wish I had found these threads before changing me turbo I could of saved myself a small fortune. Well I will be wiser next time. Hope this help someone.

[kellyrick1963]

crasher new to this site thanks for all the good advice,and when are you going to do the guide.thanks

[Crasher]

Guide? Did I promise to do one?

[as36]

I know this sounds silly but I had exactly the same symptoms on my PD130 sport 70000 miles and cured it by simply changing the air filter.

[MALH]

'iworld', have you resolved your problem yet? If so what was the fault and the result?

Thanks, MalH

[MALH]

To as36. That's always worth a try. I'll look at mine.

MalH

14.30 hrs Just tried removing the air filter. No change.

When you think about it, it doesn't seem logical that simply changing the air filter would solve the intermittant problem. But hey, whatever does the trick (and is so simple) is always worth a try.

MalH

[Izalman]

I've just left the local *********** picking up some antifreeze.
I checked the price / availablity of the MAP (rear of engine compartment on air duct) and the Thrust Sensor (down near turbo) to cure my limp mode cheaply.
MAP was factory order, Thrust sensor was off the shelf - 5 in stock.
Does one think they have problems with these little devils.........
I'll be trying the latter, as it was the cheaper of the two also.

[Crasher]

The MAP sensor and Thrust sensor are the same thing, 038 906 051 C. Do you mean the N75 valve down near the turbo?

[Mike McKinstry]

anyone know anything about the products made by innotec for cleaning turbos-comes as a 2 stage-second stage to flush out first stage.i would be interested in prices and any possible long term effects this product may have?

Mike

[Izalman]

Hi Crasher,

The little device fitted in the inlet ducting from the intercooler > manfold has the p/n 038 906 051C on it - held in by 2 torx screws, the parts guy called it the convertor? Is This the MAP?

On an earlier thread the thrust sensor p/n 1J0 906 627A was mentioned as a likely cause of turbo limp disease. This is the part they had 5 in stock, I asked to see one so I could find it in the engineroom. Is this the N75 valve?

As you say, its tucked up near the turbocharger and has a pressure accumulator next to it. Looks like I will have to both break & dislocate my wrists to fit it...

I asked about a diagnostic check, £47 inc vat which is reasonable for a ***********.

PS great footer to your user ID - love to moggy too...

Mike

[Crasher]

038 906 051 C is the Thrust sensor but is actually a combined MAP (Manifold Absolute Pressure) and IAT (Inlet Air Temperature) sensor.

1J0 906 627 A is described as a “Pressure Converter” but is more often referred to as the N75 valve.

Please don’t use that expression “********hip”, it isn’t necessary.

[Izalman]

Sorry Crasher,

Thanks for the info on the switches.

ALL modern car dealerships are a rip off. It is common knowlege that new car sales margins are miniscule. The only way they make money is on service and parts - hence the expresion. How come Euro, Andrew Page and others sell all the same none captive parts - even the same manufacturer at up to50% less.

If they dummed down the new car sales area, got rid of 50% of the metal thats taking root on the forecourt off their books, the service cost MIGHT be somewhat lower.

Sadly the motor industry's only interest is in moving metal, pity they can't focus a modicum of interest or consideration on customers with problems ie water from pollen filters wrecking CCM's.

[Crasher]

How do you expect them to survive? We do need them no matter what.

[Izalman]

Successfull businessess survive and grow by providing value for money and looking after their customers. Those who don't will fail.
I've used Autocentres for the past 5 yrs for my Passat & 405 as they abide by the simple criteria above.....

Sorry but we're off topic here:o

[Crasher]

Yes but they don't HAVE to provide a showroom and staff to sell new cars. What you want is VAG main dealers that only sell cars and VAG workshops that only provide repair/servicing facilities including warranty repairs. I imagine that the former would not survive.

[MALH]

Successfull businessess survive and grow by providing value for money and looking after their customers. Those who don't will fail.
I've used Autocentres for the past 5 yrs for my Passat & 405 as they abide by the simple criteria above.....

Sorry but we're off topic here:o

Yes we are getting off the proper topic here, but if you know what makes a successful business, I'm surprised you havent set such a 'fix it only' enterprise up and are now making a fortune...........and why didn't we all think of that!

Meanwhile my intermittant loss of power ('lack of inlet manifold pressure') is still not fixed! Does anyone know if the advertised V Checker Pro works OK and would it diagnose/identify the faulty component?

Cheers

[Crasher]

Was that the topic :D

It will read the codes yes but if you own a laptop, VAG-COM makes far more sense.

[MALH]

Thanks Crasher.

The topic is ISALMAN's insight into how dealerships should run their businesses - (3 posting above).

Can you say if the [B]'V Checker Pro'[B] gives a good diagnosis of which component is at fault.

[Crasher]

I have never used it but if it gives a fault code, you can look that up on a list.

[Izalman]

Still got problems:(

Took the car to a local VW independant for a VAGCOM check, they could not read the engine fault codes - communication error.
They could read all others:- AC, ABS etc they said it was a fault between the ECU and comms plug, anyone any idea what to do next.
They took it for a test drive and recon the turbo is donald ducked, it has the variable vanes sticking and is going into overboost. ECU is then shutting down fuel supply so not to overfuel engine to destruction. I could move the actuator arm on the vvt quite freely albeit heavily sprung loaded by the vacuum chamber.
I'm a bit sceptical of their diagnosis as I can hear the turbo when booting it in 1st & 2nd. then nothing in 3rd upward.
If I turn the engine off after a 'flat session' & remove key the fault seems less.
Now I'm really confused.

[Scratx]

Hi!
Need to replace my MAP sensor, got same limp experience described on this post.Where can I buy one online?

Thanks.

Passat 1.9 TdI 110 '98 (B5) - 87k

[Crasher]

Go to the dealer!

[MALH]

Hi!
Need to replace my MAP sensor, got same limp experience described on this post.Where can I buy one online?

Thanks.

Passat 1.9 TdI 110 '98 (B5) - 87k

The thing is, how do you know it's the MAP sensor that's faulty? There are many entries in this thread which testify to people jumping to a (wrong) conclusion and paying out for repairs/components which are not the cause of the problem. In fact, finding the exact cause is the real art! If you don't know for sure, I'm afraid Chrasher is right, - although it may go against the grain of a keen amateur. Otherwise you have to do a great deal of testing and research to narrow the fault down. Have you got the fault /DTC codes)?

Passat 1.9 Tdi 130 Sport 2002, 54k

[Mike McKinstry]

Totally agree with above.
I have had fault code 17965 charge pressure control positive deviation P1557 diagnosed by two separate VW specialists and unfortunately the technicians seem to know little more than any of us on this forum(thanks to our resident experts such as Crasher and others-you know who you are-thanks ).
I have had boost pipe from i/cooler to plastic EGR induction pipe replaced and MAP sensor replaced as well as a dose of forte ADT and have been advised by last specialist to now replace boost valve(n75) after which I should look into recon turbo-seems like the right advice comparing o diagnosis on here however I agree would be nice to be able to put your finger on one thing for definite!
My intermittent overboost has been on and off since last october and does not give a "glad to have a VW "feelin.
Only consolation both specialists have said the 130PD is much more durable and better than the 2.5 TDi which are always giving bother and in bits.
I suppose it is only a matter of time before this fault is so common we will have a plethora of specialist out there wanting to clean our VNts for £80??

Just my thoughts..
I will of course post when I have the problem sorted as when people do get a resolution they so often neglect to post their successes to the frustration of the rest of us!!
Anybody agree the N75 is next route?
Anybody able to get a sponsor to do turbo deals replacing /supplying ?

regards,
Mike

[Scratx]

Why didn't you have the fault code read done before fitting a new turbo? 17965 indicates an over boost situation which could be the MAP sensor, N75 valve, a vacuum pluming problem or even still a faulty turbo, I have seen a number of recon turbo’s still exhibit this fault. It needs someone who is experienced at these engines to spend some time with the diagnostic computer and do some tests in Measuring Blocks 08.

Hi!
I will refrase my last statement.

I may need a MAP sensor. Where can I check for parts prices online?Most sites I came across mention MAFs and N75s but not the MAP sensor.

I agree that DIY is not always the best, and sure money dont grow on trees, but there is a reasoning behind my question.
Reading various quality Audi and VW forums like this one, I found a percentage of users have solved similar problem by changing the mentioned sensor, followed by replacing the N75 valve (which I would leave for a tech).A minority have to recon/replace the turbo to get results or realize the problem is solved in some other form.
I intend to have codes read but I also have the car in good condition i.e. fresh oil, all filters, most wiring connections clean and checked, pipes checked for air leaks,clean MAF - which brough a smooth improvement- so this should be fine.So I am considering my options before spending £40 to get codes read and get the somewhat generic "replace turbo" advice that seems attached to this issue and leads to tentatively replacement of parts highlighted by Crasher.If I can increase the accuracy of the reading by making sure certain affordable parts cannot be the cause, then I am happy and maybe solve the problem.On the other hand the problem can reside somewhere else.
Neverheless it seems a common fault on tdis and this forum is here to promote informed decisions.

Thank you all for the advice.

[MALH]

Hi, me again.

You may wish to get a cheap code reader. I bought one for about £25 which will read all the codes (DTCs) and clear them from the memory. You have to do your own research to get the translations of the codes but these can be gotten off the web. Getting the codes –once again, - is not the end of the problem, e.g. you could get mine, i.e. 17964 “Charge pressure control, regulating limit not reached (sporadic fault)” Great help. This simply means I have an intermittent loss of boost pressure…..which I knew anyway, and which is why I’m reading this thread!

There are several possible causes, but if the car and the turbo are in good nick, it could probably be narrowed down to a) MAF sensor (the easiest to change and costs about £60, b) N75 actuator valve (difficult to change but only costs about £45 or £85 fitted) or c) MAP sensor, - again fairly simple to fit (don’t know the cost). The trick is to work out, or have the VW agent deduce which of these components is at fault. My recent history is not good news…..but here it is.

I took my car to the local VW agent last week for a diagnostic check (£96 incl.) to try and get the actual faulty component identified. I assumed he would have sophisticated electronic kit which could read all the data output in real time and pinpoint the problem. What happened was, a) he could find no DTC stored, - which was there when I took the car in and b) the technician ran the car round the block and reported loss of power! He then said my car (52 plate 1.9 AFV 103 PD) was too old to carry out an electronic check on, so they used their workshop experience and changed the MAF sensor, for £105 incl. He then road tested the car again and said ‘it wasn’t fully cured’ so they would have to change the N75 actuator valve for £84 but they didn’t have one in at the time. I took the car for a spin and FOUND NO IMPROVEMENT AT ALL and the DTC still showing. I took it back and they said OK, we’ll get the old MAF sensor out of the recycling bin and put it back in and refund my £105. I won’t break your heart with any more, - suffice to say that if anyone knows of any professional who knows his stuff on VAG engines and is in the north west, let me know. I’m still in correspondence with my local agent.

[MALH]

CLOSURE AT LAST!

Further to my last posting, I took the car back on Wednesday day. This time they COULD find the stored fault code (17964 as above). This allowed them to use the VW ‘Guided Fault Finding’ programme and used that the identify the fault as being in the N75 valve – apparently when powered (12 volts) it can heard or felt operating….or not, if is broken. They fitted a new valve (£25 + vat + fitting) and re-fitted my old MAF sensor (foc), and rechecked the fault codes and the performance. No faults show up and the car runs like new. They refunded the cost of last week’s supply and fit a new MAF sensor. I now have pages of printout from their diagnosis, detailing the guided fault finding procedure and I feel a lot more satisfied.

One interesting thing was that the workshop supervisor said that not many of the mechanics had ever used the procedure or fitted an N75 valve, which echo’s Mike McKinstry’s experience. He said “We don’t usually get many cars as old as yours to work on.” Mine is a 52 Reg!!

Now I have the old valve, I can see it is not a complicated component (sorry I can't upload the photo at the moment). It’s simply a cylindrical valve rotated by an electric motor/solenoid which allows the vacuum to pass to the turbo actuator and the EGR valve. It is held in place by two small bolts and whilst a bit fiddly to replace, it doesn’t need any significant dismantling etc, so if you know it is faulty, it could be worth trying to replace yourself. The vacuum plumbing is just like screen wash tubing.

To Mike McKinstry, try to talk to the VW people carrying out the diagnosis as I’m sure their ‘Guided Fault Finding’ programme will pin-point the problem. It really does talk then through it step by step e.g. “Switch on ignition, listen/feel for vale operating” etc etc.

To Scratx, the quote below is from a great American VAG forum site (sorry I can’t recall what it is) and the info re the N75 valve is sound. You may want to try the “Blow or flush it through” method. Depends on how much time you can spend with the car down. I haven’t done it but from my picture and the explanation it could be worth try.

Best of luck.

Quote from Forum:
- Turbo boost control solenoid valve problems - this is also known as the N75 valve. If you have VAG-COM, and a trouble code of "intake manifold pressure control" is being set, and the problem is NOT a sticky VNT mechanism (see above), the N75 valve may be sticking, clogged with debris, or faulty. It can be removed from the vehicle and the paths through the valve checked by blowing through the various connections with the valve first de-energized, and then energized with 12 volts. Alternatively, obtain a vacuum gauge and "T" it into the hose that goes from the N75 valve to the VNT vacuum diaphragm, and confirm that the vacuum varies under different load conditions while driving. If found to be faulty, some have had success by blowing solvent through the valve to remove any deposits, but replacement with a new one may be the best option.

[Mike McKinstry]

To MALH,

Firstly congratulations on solving your "limp" problem-bet you feel chuffed.
Also dont you feel great being able to tell the specialists what to do!Thanks to all on this forum.
Perhaps you could scan and post the page of the guide?
Also thank you for posting the solution to your problem something so many fail to do which adds such alot to this site.
I was going to fit N75 but had to take car abroad for half term -400 mile there and had ,I think ,3 limps and then nothing 400 mile back so will see what happens.
(On an aside also drove brand new 2.0T TT whilst off with auto/paddle box and very impressed.)

Note my post today on water ingress-finer detail.

Regards,
Mike

[IshH]

I had a similar problem with no turbo - after spending an obscene amount of money on new sensors it turned out to be a cracked pipe to the sensor - so it wasnt creating the pressure/vacuum and giving a false error code.....

Price of replacement pipe... 50p - I was gutted!

Check those out too.

[veedub76]

My Wife has been has been having the same problem with her 130 TDI passat and i took it to a VW specialist, firstly they swapped the MAP sensor from an Audi A4 and this has no effect, they then tried a new MAF and still no effect.
They then had an Auto electrician measure the readings going to the N75 i think and this was ok. They then found a split vacum line running to the pressure convertor so they call it, te covertor is knackered as the split line has allowed crap to be sucked in, replacement part being put on today which they say will cure the problem and the vacum line is repaired too.

The codes we had were 462C or 17964 low boost pressure. Car was going into limp mode sporadically, mainly up hill, but the boost was coming in later at over 2000rpm, thenit would go into limp mode.

Check all your vacum lines for leaks:approve:

[Crasher]

17964 is nearly always a vacuum leak, a quick 10 second test would have showed the leak and been fixed in under five minutes.

[martin1810]

17964 is nearly always a vacuum leak, a quick 10 second test would have showed the leak and been fixed in under five minutes.

Yes...but thats in a proper garage like yours. :D

[Crasher]

Ohh you bitch! :D

[pete99]

Ohh you bitch! :D
Oops !!
Latest -development on my 3000 miles a year A6 (1.9 TDI)
fault code- 17965 charge pressure control--positive deviation. p1557
static no define .

Is that a 'new one' ?. :(

[Crasher]

17965 is about as new as the hills… In the vast majority of cases it is due to sticking turbo vanes or actuator, sometimes it is a faulty MAP sensor, occasionally a faulty N75 valve and rarely the AMM but this does happen, I have seen it twice.

[pete99]

17965 is about as new as the hills… In the vast majority of cases it is due to sticking turbo vanes or actuator, sometimes it is a faulty MAP sensor, occasionally a faulty N75 valve and rarely the AMM but this does happen, I have seen it twice.
ok- fair point-- but- where does the 'positive deviation' fit in ?.:confused:

[Crasher]

It means it is over boosting, a positive deviation rather than 17964 which is underboost, a negative deviation. What year and engine code is your car?

[pete99]

It means it is over boosting, a positive deviation rather than 17964 which is underboost, a negative deviation. What year and engine code is your car?
It's a 53 reg (c5) AWX 403490 (number).
cheers

[Crasher]

The VW definition of the code is

17965 P1557 Charge pressure control Regulating limit surpassed

Their possible cause is “Hoses interchanged, not connected” which is a cause I forgot to mention but a rather rare one at that. The MOST common cause is a clogged up turbo. The fist step I would take would be to check the operation of the N75 valve and its vacuum control system in Basic Settings 04, Main Group 011 with the engine running at idle. This should make the turbo vane operating rod move visibly along a stroke of about 10-mm every 15 seconds or so. If it does, it still may be that the turbo is clogged but I would also then observe the MAP sensors output in Measuring Blocks 08, Display Group 011 Display Zone 3 to see if the mBar reading made sense against the specified reading in Zone 2, I often use the graph function to make this clearer.

[fleamoo]

I was getting intermittent overboost a few months ago. Tapping the actuating rod as per Crasher instantly cured it, and it hasn't returned so far.
I didnt actually use vag com to assist at the time, just started and stopped the engine to "exercise" the vanes.
After a couple of taps there was a small but noticeable increase in actuator travel.
I must admit i wasn't really expecting this to work on an intermittent fault, but i seem to have got lucky. Cheers all.

[pete99]

The VW definition of the code is

17965 P1557 Charge pressure control Regulating limit surpassed

Their possible cause is “Hoses interchanged, not connected” which is a cause I forgot to mention but a rather rare one at that. The MOST common cause is a clogged up turbo. The fist step I would take would be to check the operation of the N75 valve and its vacuum control system in Basic Settings 04, Main Group 011 with the engine running at idle. This should make the turbo vane operating rod move visibly along a stroke of about 10-mm every 15 seconds or so. If it does, it still may be that the turbo is clogged but I would also then observe the MAP sensors output in Measuring Blocks 08, Display Group 011 Display Zone 3 to see if the mBar reading made sense against the specified reading in Zone 2, I often use the graph function to make this clearer.
Thanks Crasher - I appreciate your interest and help.
However - seeing as i'm only a rough @rsed builder who only has a micky mouse type code reader-- It's a bit above my head .
Theres only so much information a brain can take in- and store -and the older we get-- the less we feel the need to know !!.
Now- on the other hand - if theres anything you wish to know about building , structural problems etc---feel free to ask (I'm a mine of information in that field).
Since cars became full of 'plug ins' and 'chips'-- I just gave up in that field .
This website is a mine of infromation and helpful to people like myself --saves us ££££s and hassle.
People like you- who take the time and trouble to help -- are worth their weight in gold to us 'other trades' drivers.
Thanks,
Pete

ps - Having read some of your posts from a few years ago-- I cant help notice - you are getting grumpier and less patient these days !! ;).
I'd bet Mrs Crasher agrees ?.

[Crasher]

Ohh god not you as well, yes Mrs C does think I am a grumpy old *******.

I have read some of my own stuff from years ago in the Golf + mag that I stated writing for in 1996 and I was a lot less up my own **** then, maybe I should lighten up a bit. Mind you, I think my writing style comes over more grumpy than I actually am, it is probably partly due to me thinking too much about what I am putting rather than how I am putting it, I think I come over better in person, I hope.

Right it is past 6pm so I am going to pop open a bottle of red, back in a bit.

[pete99]

Ohh god not you as well, yes Mrs C does think I am a grumpy old *******.

I have read some of my own stuff from years ago in the Golf + mag that I stated writing for in 1996 and I was a lot less up my own **** then, maybe I should lighten up a bit. Mind you, I think my writing style comes over more grumpy than I actually am, it is probably partly due to me thinking too much about what I am putting rather than how I am putting it, I think I come over better in person, I hope.

Right it is past 6pm so I am going to pop open a bottle of red, back in a bit.
Its a age thing- Mr Crasher ,
I'd guess you were maybe 54,55,56 .
Dont worry-- in a year or 2 - you will take things a little easier and handle all the 'repetitive questions' much better . haha.
I'd take a bet- thatyou wake up several times each night- thinking of answers to questions people ask you !!. Mrs Crasher is used to it so- dont worry.
Anyway- apart from cars -- have you any other interests ?. ;)

[Crasher]

MID FIFTIES!!!! Splutter-cough, you could take a dislike to some people…:D nearly 47 actually.:1zhelp:

Mrs C gets tired of WWII data books (reading volume one of http://www.aerospacemasterbooks.com/series.asp (http://www.aerospacemasterbooks.com/series.asp) at the moment) or Snap On and Klann tool catalogues cluttering up the floor.

[pete99]

MID FIFTIES!!!! Splutter-cough, you could take a dislike to some people…:D nearly 47 actually.:1zhelp:

Mrs C gets tired of WWII data books (reading volume one of http://www.aerospacemasterbooks.com/series.asp (http://www.aerospacemasterbooks.com/series.asp) at the moment) or Snap On and Klann tool catalogues cluttering up the floor.
Oh !! premature grumpiness - never mind -just carry on helping people on here - and realise - your advice is much appreciated bud :biglaugh:

[pete99]

Oh !! premature grumpiness - never mind -just carry on helping people on here - and realise - your advice is much appreciated bud :biglaugh:
OK- latest update -
Its been sat on drive for over a week. So- took it out for a spin today to see what happens.
'Red lined' it in 1st, second and third --for about 30 miles . Not a sign of a problem . Ran like a dream .:confused:
On motorway felt a bit lumpy at 100 but - think its a wheel balance thing.
not gonna hit 3k miles this year in Audi (too busy working) .

[pete99]

Oh !! premature grumpiness - never mind -just carry on helping people on here - and realise - your advice is much appreciated bud :biglaugh:
I just love those old German planes- especially the Fokkers.
Reminds me of that Stan Boardman joke on tv . (the one that got banned and cant be found ) (' I must shoot that Fokker down' joke).:biglaugh:
Anyone remember that one ??

[Crasher]

Anton Fokker was Dutch, you mean Focke-Wulf .

[pete99]

Anton Fokker was Dutch, you mean Focke-Wulf .
OH !! sorry mine fuhrer;)

Yeh- its that lot of fokkers who bombed the liverpool chip shops I guess.:D

[daveybuc]

hello mate, i had the same problem and 2 diagnostics didnt find a fault, what the problem turned out to be. was the turbo boost control valve... i took it off blasted it with wd40 shook it clean put it back on and drove the motor and it was perfect for a mile or so and then i lost power again...these valves are renowned for clogging up...try this and see if it helps if so DO NOT BUY A REPLACEMENT FROM A DEALER....£50-95 THATS WHAT VW AND SEAT QUOTED...i bought one brand new of ebay with one years garantee for £25 free postage....best wishess david.....

[pete99]

hello mate, i had the same problem and 2 diagnostics didnt find a fault, what the problem turned out to be. was the turbo boost control valve... i took it off blasted it with wd40 shook it clean put it back on and drove the motor and it was perfect for a mile or so and then i lost power again...these valves are renowned for clogging up...try this and see if it helps if so DO NOT BUY A REPLACEMENT FROM A DEALER....£50-95 THATS WHAT VW AND SEAT QUOTED...i bought one brand new of ebay with one years garantee for £25 free postage....best wishess david.....
Thanks for that Dave .
My car hasn't moved much since my last post- but when it has -- I dont use 5th gear - I just have a cunning plan . Have stuck to 4th and revved the sphericals off it -- Just trying to figure out if it will blow some of the cobwebs away !!. My figuring is- a few more ££s of fuel is far cheaper and easier than a new turbo. (that is - if it IS the turbo--of course).
:beerchug:

[daveybuc]

Thanks for that Dave .
My car hasn't moved much since my last post- but when it has -- I dont use 5th gear - I just have a cunning plan . Have stuck to 4th and revved the sphericals off it -- Just trying to figure out if it will blow some of the cobwebs away !!. My figuring is- a few more ££s of fuel is far cheaper and easier than a new turbo. (that is - if it IS the turbo--of course).
:beerchug:
hello mate, the reason my boost control stopped working was due to the oil seals in my turbo were perished and oil was getting blown up through the intercooler into the egr valve and because the boost controler is along this line it was getting clogged with oil....the only way to reslove the problem was to have the turbo recondioned...£320.00 later its back in with new controler and the cars pulling like a train....so check your intercooler pipes for oil they should be clean and dry........best wishess davey.....

[Crasher]

If I ever see one that has clean and dry pipes I will be shocked, I have seen cars with oil dripping out of the pipe junctions with only 17K miles on the clock from new.

[pete99]

If I ever see one that has clean and dry pipes I will be shocked, I have seen cars with oil dripping out of the pipe junctions with only 17K miles on the clock from new.
Was that in the 'old days' ? old timer !! :D
Anyway Crasher - if anyone would know -- it must be 'you'-- how come I'm still a new member ?.

[caldirun]

hello mate, the reason my boost control stopped working was due to the oil seals in my turbo were perished and oil was getting blown up through the intercooler into the egr valve and because the boost controler is along this line it was getting clogged with oil....the only way to reslove the problem was to have the turbo recondioned...£320.00 later its back in with new controler and the cars pulling like a train....so check your intercooler pipes for oil they should be clean and dry........best wishess davey.....
The boost control valve is only conected to the vacuum system, how did it get clogged with oil?

[Crasher]

how come I'm still a new member ?.

Because your memebr is newer than mine…:D

[fahad]

hi your turbo is gone for good or get same one rebuilt

[viperwhite]

hi to any one out there with stickt vanes on their turbo, i have the soloution. rather that dismantle the turbo, on my a6 tdi i undid 3 bolts and disconnected the exhaust from the turbo, then sprayed releasing oil, not penetrating fluid, this releasing oil had added graphite particles in it then moved the actuator up and down for 10 mins, took it for a spin and now no limp mode or problems. goes like it should. advantage is i can do this when i want and it only takes 25 mins. sorted. releasing oil costs £3.99.

[martin1810]

Given the temperatures in the exhaust I will be surprised if releasing oil works as a long term fix. Keep us posted.

[viperwhite]

i think what happened is that soaking it in releasing oil, the oil doesent evaporate like penetrating fluid etc and moving the actuator up and down loads caused the carbon to rub off and break up and stay suspended in the oil then when i took it for a drive in the first couple of seconds the turbo blew the oil out containing all the carbon deposits. my actuator moved halfway up then there was a bit where it was stiff, i found out that the car had motorway miles 200k at the moment so im guessing carbon built up whilst vanes in a certain position but its all smooth and seems ok. i did this probably 2 months ago and so far no probs. i do hear a whossshing noise when i floor ity but stops as i ease off throttle so im guessing i didnt clean it enough, no more limp mode. used to go into limp every ten mins before. seems this is a good cheap fix. ill keep you all updated.

cheers

[caldirun]

seems this is a good cheap fix. ill keep you all updated.

cheers
May not be a cheap fix if it kills the cat.

[pete99]

Update to me - still running in 4th gear -tops !!.
Runs great ! no limpmode whatsoever .
Same fuel economy as when I used 5th gear . 29 MPG !! :biglaugh:.
Nah- just a joke - 42 MPG -steady.
Hey- acceleration at top end is great in 4th --much better than 5th . ;).

[viperwhite]

May not be a cheap fix if it kills the cat.


which is why you start it up with out the cat connected to burn and blow out all the oil 1st

[charlieboy180]

hi sorry for jumping in

i had my turbo vanes cleaned and still have black smoke and not much power i do think the turbos is working coz it sounds like it is whossing a bit.. where is the map sensor located on my audi a4 1.9tdi 1998 AFN engine code
just i have read on here it could be built into the ECU

[martin1810]

Your symptoms sound like a turbo not blowing, pipe disconnected or faulty egr. What does a vcds read say.

[charlieboy180]

i have had no codes read yet just my mates a mechanic he cleaned the turbo said the turbo was at fault i changed the maf sensor still the same but the turbo whistles does that mean it is working or not

thanks

[martin1810]

I wouldn't do any work on the car without a code read. That's a waste of time. You can't guess what the problem is.

[charlieboy180]

will have the error code done on Tuesday thanks

[caldirun]

which is why you start it up with out the cat connected to burn and blow out all the oil 1st

"hi to any one out there with stickt vanes on their turbo, i have the soloution. rather that dismantle the turbo, on my a6 tdi i undid 3 bolts and disconnected the exhaust from the turbo, then sprayed releasing oil, not penetrating fluid, this releasing oil had added graphite particles in it then moved the actuator up and down for 10 mins, took it for a spin and now no limp mode or problems. goes like it should. advantage is i can do this when i want and it only takes 25 mins. sorted. releasing oil costs £3.99."

Can't find any mention of starting up without the cat connected, sorry the crystal ball's playing up, I'll have to get a new one!
Do you run it for 10 minutes with the cat off? (must have forgiving neighbours!) or go for a spin then fit the cat back on? (morning constable!)

[charlieboy180]

just a update got codes read maf faulty but i replaced the maf sensor about a couple of months ago(ebay cheap maf) now i took it off to check it and there is no sensor wire and diode its missing i also checked my bosh maf sensor and that to is also missing the wire and diode

where is the best place to buy a good maf from

my lesson to be learnt about buying cheap maf sensors from ebay dont and have codes read

[macquatic]

where is the best place to buy a good maf from



Your local dealer.

[Crasher]

They don’t have a sensor wire, they are hot (or thin) film and the AVF/AWX engine AMM does not have a temperature sensor so no temperature measuring bead.

[charlieboy180]

my fault for the miss understang i jumped in this post my car is a audi a4 1.9tdi 1998

[Crasher]

Still a four wire AMM with a hot film sensor and no temperature sensing. The temperature sender is inside the boost pressure sensor.

[charlieboy180]

we must have wires crossed iam talking about a mass air flow meter i thought buy taking it out off the housing to clean it there was no wire there to clean it was broken off thanks for the reply

[Crasher]

No wires crossed old boy, the correct name for what you call a Mass Air Flow meter is (according to VAG parts) Air Mass Meter G70 or sometimes referred to as an Air Volume Meter in the workshop information system. MAF is an Americanism that I refuse to use.

[martin1810]

we must have wires crossed iam talking about a mass air flow meter i thought buy taking it out off the housing to clean it there was no wire there to clean it was broken off thanks for the reply

Only the early ones had a wire. Later ones are a plate that you can wipe clean. Cleaning these doesn't usually have much effect. You can check how well the MAF is working with vag-com measuring blocks. Details are on my site.

[charlieboy180]

hi here is photo of a mass air flow sensor same as mine but the 2 i have the wire with a little diode is missing a vagcom reader says maf http://www.guzzimental.com/images/alfa/Bosch%20MAF%20thermistor%20text.jpg

[Crasher]

And VAG-COM was written in which country? :D

[charlieboy180]

dont know what you mean iam from the uk the fault code came up in the book as mass air flow sensor if the wire is missing on my sensor does it mean it is broke

[Crasher]

VAG-COM is American, hence the American term used. As far as I am concerned your Air Mass Meter does not have a hot wire sensor so you will not see a wire, it uses hot film technology.

http://rb-kwin.bosch.com/en-PL/start/sensorik/heissfilm.html

[charlieboy180]

ok i see what you mean the glass thermistor is missing from my Bosch and i bought a cheap one off ebay and now that too is also missing the glass thermistor is it common for these to come off

[yaman]

When you get the new sensor, you have to pop the hood
and get your tools outta the trunk.

Regards
Jim

[Crasher]

I didn’t think the four wire AMM’s had one.

[pete99]

No wires crossed old boy, the correct name for what you call a Mass Air Flow meter is (according to VAG parts) Air Mass Meter G70 or sometimes referred to as an Air Volume Meter in the workshop information system. MAF is an Americanism that I refuse to use.
Still grumpy- I see . :(

[Crasher]

I can't remember if I was then or not :D

[westie383]

I knew my turn would come along eventually, after reading for years about TDi's loosing power, my 2001 130TDi AWX,85k miles, finally succumed to the black gunge. The power had really dropped off, even though it would still eventually get to 100+ (short burst for testing purposes, your Honour). Anyway, after reading through this thread, I decided to strip out the EGR, and it was pretty much in the same state as in the pics provided by Pete K's excellent write up, so this was duly cleaned and de-coked. Whilst I was at it, I took out the MAP, and this also had a coating of black slime, so I sprayed computer cleaning solvent on it (safe on plastics), flushing it clean. It might be worth cleaning the MAP before replacing it, as mine had gunge between the flat plate and the temperature bead, which can't have been helping matters.
All re-assembled now, and once more it's pulling like a train, and as far as I can tell, there's no sign of the clouds of smoke when flooring the pedal after trundling around i.e. slip roads and junctions.
Thanks once again to the previous contributors to this thread, especially Crasher.

Trev.

[passat tdi130]

i have a niggly fault with my passat sometimes especially when just started hot or cold i get what i can describe as the car holing back as if there is no boost if i dip clutch give car a quick rev it goes ok..! until the next time .. i have had it do it once or twice while sat at a set of lights gone to accelerate away and the bugger hold's back again

any help idea's

p.s. never throw's a fault code i read it quite regular

[Crasher]

Change the Air Mass Meter for a genuine VW exchange unit and see what happens.

[passat tdi130]

the AMM could really cause this prob..?

[Crasher]

Sometimes but in the absence of any fault codes and with a power delivery issue the first thing I always do is change the AMM. This is mainly because spending time analysing it costs the customer more than the £80 odd that a genuine AMM costs and it is surprising how often it is the AMM in situations like this. Without any codes it is all I can suggest.

[passat tdi130]

hmmmm another thing to mention is when it does it the engine noise seems a bit how can i describe it..! throaty like a gawwwwwww type of noise then as i say give it a quick rev and all is ok again

im just about to change the thermostat as well with my temp dropping problem the engine always seems to be running at about 80 to 85 degrees on the temp gauge

it used to sit at 90 regardless of weather hot or freezing cold.. so here we go hopefully i dont have to remove alternator to do it..!

[pete99]

Because your memebr is newer than mine…:D
Just occurred to me - I was on here a year before you joined .
Mind you- it was later in evening when you replied . !!!!!!!!!!!!!!!!!!!!!!!!!!

[smithy602179]

i had loss of power and throaty noise on my 2l passat and after changing secondary air blower it runs a treat , might not help u out tho .

[Crasher]

That would be a petrol engine then...

[maf]

Hi guys
Wonder if you can help ?
My 130 sport tdi y reg (190,000 miles) has lost power, black smoke,occasional whirring sound,struggles to rev over 2000 rpm under load and i cant here turbo working when revved whilst stationary.
I suspect knackered turbo
Any ideas ?

[Crasher]

It could be but it could also be a split/detached hose or a failed sensor, why not use the system VAG gave you with the car and get it fault code read, much more reliable than guess work or panic stations. If the codes don't help, then some measuring block work is next, i.e. proper mechanicing....

[maf]

Hi guys
Wonder if you can help ?
My 130 sport tdi y reg (190,000 miles) has lost power, black smoke,occasional whirring sound,struggles to rev over 2000 rpm under load and i cant here turbo working when revved whilst stationary.
I suspect knackered turbo
Any ideas ?

Proper mechanicing was required !
2nd hand turbo fitted
Egr valve and inlet manifold cleaned (how cacky!)
Jobs a good un!

[unclespevie]

well i removed the egr,inlet and decoked the Mr M foamy way, also when the inlet was off i did the turbo as well, popped a pipe down in there and squirted untill i just saw it......back together, fired up and left a huge black circle on my drive....man some crap came outta there.....and the egr is working as it should......

i left the foam on the egr about 1 hr, washed off and did again to get a clean job.....

all i have done to my car i got the info from here.......cant argue with can you now????? great

kevin