Turbo Wastegate problem

[bigmikeyoyo]

Hi Guys
After blowing my second intercooler to bits I've spent the day working on the the wifes 02 1.9tdi with 155k on the clock.
Basically ever since I got a friend /mechanic to replace the first intercooler and EGR valve theres been a noise from the engine like a fluttering on changing gear. The turbo actuator is free ok but it has permanant vacuum going to it and so it is permanantly keeping the vanes closed resulting overboost and the car going into limp mode when on boost at about 3000 revs, ignition off and on again it resets itself.
Also theres no vacuum at all going to the EGR valve so its doing nothing at all. Is my n75 faulty, I cleaned the MAP sensor today and the MAF sensor so am ruling these out unless the map is done after the first intercooler blew at 90mph on the M5.
I'm inclined to say the N75 is the culprit but would like to hear any thoughts on the matter.
Thanks in advance
Mike

[Doctle Odd]

I'd say you have sticky vanes no wastegate on an 02 AFAIK Search Google for sticking vanes they can be cleaned fairly easily

[bigmikeyoyo]

Sorry I meant vanes not wastegate, done the mr muscle clean twice in the past 3 days , as I said the actuator rod is moving freely but due to the permanent vacuum to it it is constantly in the up position even when under load it is not operating the vanes to release boost, is the problem therefore not electrical as the n75 should control the vacuum to go on and off when needed instead of having it on all the time as I do

[Doctle Odd]

You need a diagnostic scan mate electrical guesswork won't work

[zollaf]

the way vny works is that it does have a permanet vacuum to it. no vac means no boost. as the boost rises then the n75 reduces the vacuum to control the boost. think of it as working backwards to a wastegate. as doc says, you need a scan to get to the bottom of it, but you also need to know how these things work to be able to fix them.

[bigmikeyoyo]

Why thanks for the helpful replies, scan it is then

[Doctle Odd]

Thanks for the patronising reply Zolaf but Perhaps you misunderstood my post, the actuator is having permanent vacuum ALL the time, the N75 is not releasing ANY vacuum on boost which was my point, I know I need to get a scan but as I couldnt last night at 9.30 pm I thought I'd post on here for any ideas, my mistake, off for a scan shortly so no more replies needed thanks

You don't catch flies with vinegar and you don't get free advice from an expert like Zollaf by being rude

[zollaf]

there are 2 L's in zollaf. don't get the hump, i am trying to help you fix your car from a long way off, without knowing you or your car, without having a clue about you mechanical knowledge. to me you don't seem to have a clue what you are doing, what your turbo does or what the parts of it are called, so pardon me for trying to help. and sorry if it came over as being a bit patronising, i will try harder next time to really **** you off.

[bigmikeyoyo]

Cheers Zolaf��

[Doctle Odd]

I'm sending him a pdf of the inlet/exhaust system as I type. I love rude ignorant stupid people

[bigmikeyoyo]

Come on mate no need for personal insults but the pdf would be handy thanks

[Doctle Odd]

Come on mate no need for personal insults but the pdf would be handy thanks

In a pigs eye

[Sam]

Play nice kiddies.

[Doctle Odd]

Play nice kiddies.

OK :sad6: Sam. @ bigmikeyoyo sorry for appearing rude having said that I would rather not send you a PDF

[zollaf]

:sad6::fest30:

[stuart]

I'm sending him a pdf of the inlet/exhaust system as I type. I love rude ignorant stupid people


OK :sad6: Sam. @ bigmikeyoyo sorry for appearing rude having said that I would rather not send you a PDF


Why offer to send a PDF then say you would rather not.... :confused::confused::confused:

As Sam said... Play nice... :)

[Cavanmick]

Why offer to send a PDF then say you would rather not.... :confused::confused::confused:

As Sam said... Play nice... :)
Why ask for help and then be rude about it when it's offered to you????

Mick

[Doctle Odd]

Why offer to send a PDF then say you would rather not.... :confused::confused::confused:

As Sam said... Play nice... :)

I was being sarcastic I apologise for offending anyone's sensibilities

[stuart]

No problem, after all I hope we are all here to help each other ;)

[zollaf]

there should be no vacuum to the turbo actuator when the engine is stopped. as soon as you start the actuator should move to its full extent with full vacuum applied. switch the engine off and the vacuum should stop. as revs increase and at about 3k rpm under any load, the n75 reduces vacuum to lower the boost, or rather keep it at a level. if it doesn't and the boost goes too hight then the ecu reduces fuelling and thus power and this is lim mode switch the ignition off and back on and this clears, normal service resumed. a scan should produce and overboost code, and if you view the boost in live data you should see whats happening.

[bigmikeyoyo]

there should be no vacuum to the turbo actuator when the engine is stopped. as soon as you start the actuator should move to its full extent with full vacuum applied. switch the engine off and the vacuum should stop. as revs increase and at about 3k rpm under any load, the n75 reduces vacuum to lower the boost, or rather keep it at a level. if it doesn't and the boost goes too hight then the ecu reduces fuelling and thus power and this is lim mode switch the ignition off and back on and this clears, normal service resumed. a scan should produce and overboost code, and if you view the boost in live data you should see whats happening.

Thank you for the comprehensive reply Zollaf, had the car scanned and it produced codes 17552 Maf sensor and 17965 overboost , should I therefore change the MAF or begin with something simpler?
Thanks in advance
Mike

[zollaf]

hmm, could well be the maf causing it but i wouldn't want to change it just yet. i would first want to get the opinion of crasher, see what he says. it probably is the maf but at 150 odd quids i wouldn't want to say yes just yet. if you do replace it do get one from a dealer as there are a lot of hooky ones about that give more problems than they cause.

[green A8]

I wonder where most of the hooky ones come from Zollaf? Not those pesky auction sites again!

[bigmikeyoyo]

Hi , heres where Im at now, the only code being shown now is 17965 overboost positive deviation. As the vacuum is not releasing on and off to the turbo actuator rod and staying permenantly on is my problem the N75 valve, Ive read here the pipe from the N75 to the air filter can block causing this to happen so I will check this and failing that should I replace the vacuum lines to/from the N75 even though I can detect no obvious leaks?

[arman123]

Looks like turbo replacement

[bigmikeyoyo]

Looks like turbo replacement
Not sure why youve said that Arman, turbos been checked and I was told its fine and the cars pulling like a train up to around the 3000rpm mark , surely it wud be better to try the N75 and vacuum lines first?

[adamss24]

If the turbo mechanism is fine and the rod is moving up and down freely then all points to the actuator- however all that i have seen faulty were not going up as the diaphragm inside broke so the actuator would not hold vacuum. Do you have a vacuum pump to test otherwise it's new actuator time ?! The last fault code- overboost condition points to the vanes getting stuck in the closed position, however that will force the ecu to limit the fueling in order to stop the engine destruct itself. MAF can also do similar symptoms but if you log the MAF you will see that the ECU disregards shoddy values and substitutes them with a fixed 500mg/stroke... Best to do a boost log of measuring blocks 01, 04 and 11 in 4th or 5th from 2000 to 4000 rpm's then post the CSV file on the forum so we can look at it !

[arman123]

I had the same code few years ago on my car changed maf n75 valve did not cure it it was the turbo clogged up with carbon changed the turbo and that's what fixed it
how many miles on the car ?

[arman123]

If you had a leak in the vac lines you would get negative deviation not positive just had a look at your first posts and at 155k turbo clogging up with carbon is what I think it is have you got Vcds you can cycle the actuater using the software just google it there is instruction online showing how it done

[green A8]

I had the same code few years ago on my car changed maf n75 valve did not cure it it was the turbo clogged up with carbon changed the turbo and that's what fixed it
how many miles on the car ?

I've just dug out some notes I kept on the repair of a 1998 1.9 TDi AFN engined Avant with 178,000+ miles on the clock. Same problem as OP describes, and same fault code recorded Replacement N75 valve and all vacum lines replaced, this proved to be ineffective. As did squirting oven cleaner into the turbo, several times! The problem persisted. Out of pure flustration I replaced the turbo with a known unit from a car that was written off and being reduced to spare parts. Problem solved.

The old turbo was dismantled and found to be exactly as 'arman 123' described, choked with carbon. This turbo was later stripped further and cleaned, it's a very easy job to do with the turbo off the car. The turbo was then re-built and re-fitted to another Audi. It remains in service to this day.

The bottom line is that this trick of squirting oven cleaner or similar, won't work on every occasion. Regardless of what some people say. TBH I can't see the point in even trying. The turbo on these cars is easy to remove. stripping, cleaning and re-assembly isn't a difficult job.

[bigmikeyoyo]

27164

[bigmikeyoyo]

27164
Hi guys thanks for your help so far, please tell me this, you can see the turbo actuator in the picture, the vacuum line to it connects a pipe that comes out of the bulkhead that appears to have permenant vacuum hence my overboost code, the vacuum pipe is NOT connected to the N75 surely this is not right. You can see the pipe its connected too just to the left of the egr valve coming out of the bulkhead

[Cavanmick]

I would replace all those vacuum pipes first buddy, the one from the anti shudder valve looks particularly bad and any vacuum leak causes strange issues on these.

Mick

[bigmikeyoyo]

I would replace all those vacuum pipes first buddy, the one from the anti shudder valve looks particularly bad and any vacuum leak causes strange issues on these.

Mick
Thanks Mick yea theyre 15 years old but all been tested and ok but will be replaced soon, I was also told leaky lines would likely lead to underboost not over, do you think thats the correct line attached to the actuator?

[Cavanmick]

I'm not 100% sure.whether it's right or not, I will have a look at my 130 a6 at dinnertime for you and post back where my pipe goes to if that helps.

Mick

[bigmikeyoyo]

I'm not 100% sure.whether it's right or not, I will have a look at my 130 a6 at dinnertime for you and post back where my pipe goes to if that helps.

Mick
Fantastic thanks!

[Cavanmick]

Just had a look and mine goes from waste gate off down the front of the engine, can't see where but I presume it goes to a solenoid or valve down there.

Mick

[zollaf]

yeah, the n75 is tucked down the front somewhere. the pipe from the actuator should go to this and then the n75 has a permanent vacuum and an electrical plug connection. i wonder if someone has done an n75 deletion or something silly.

[Cavanmick]

yeah, the n75 is tucked down the front somewhere. the pipe from the actuator should go to this and then the n75 has a permanent vacuum and an electrical plug connection. i wonder if someone has done an n75 deletion or something silly.
It looks that way alright, pipes going in a totally different layout to mine.

Mick

[bigmikeyoyo]

[QUOTE=Cavanmick;947472]It looks that way alright, pipes going in a totally different layout to mine.
I know the car and its not been messed with the only thing I can think off is a guy a friend of a friend replaced the Egr for me in october and its not been right since, i think the pipes are connected totally wrong and this is the root of my problem, if I could get a diagram or pics of how they should be connected Im sure I could easily fix them cheers guys

[Cavanmick]

I can't help with pics I'm afraid as mine has an egr cooler and the pipes all go down towards the front so can't see which connects to where.

Mick

[bigmikeyoyo]

No probs mate thanks for help much appreciated

[Cavanmick]

I will have a better look at it at around 5 when I'm on lunch and see if I can get a bit better info for you.

Mick

[zollaf]

if you look down the front of the engine where the turbo pipes are you should be able to see the n75 valve sat there.

[bigmikeyoyo]

Yes mate I can see where the N75 is and the pipework from it none of which goes to the turbo actuator, I need a diagram or a pic of a similar car to put it right
Mike

[Cavanmick]

OK the only thing I can see for certain is as zollaf says and that's the pipe to the actuator comes from the top pipe on the n75 valve, try that and see how it runs, you can cable tie the anti shudder valve open if it's not getting vacuum.

Mick

[arman123]

27169

is this any help 2002 1.9tdi

[bigmikeyoyo]

Thanks guys, this is deffo my problem, just need to work out where the pipes that are presently connected should be but Armans diagram will help, will get onto it first thing tomorrow as heading to Ravenhill now to watch the Ulster match, once again thanks and I'll let you know how it goes tomoro
Mike

[Doctle Odd]

Send Crasher :notworthy a message, he often posts diagrams of things and he is a bloody nice chap too

[bigmikeyoyo]

Hi guys, just an update to say the cars fixed and going like new. Vacuum pipes were connected wrongly took me 2 mins to fix, moral of the story is dont let a mate of a mate work at your car, lesson learnt for me. Thanks for all your help and apologies to anyone I may have ****** off along the way (zollaf)