engine trouble code 17965 - turbo dying? HELP!!

[Eshrules]

once again guys, i need your help please! going down the motorway the other day, lost all turbo power after i shifted out of 4th at about 2900rpm into 5th, no power whatsoever, pulled on the hard shoulder for ten mins and it was back to normal.

everytime i rev near to 3000rpm, it does the same again! trouble code has been logged, but no engine check light trouble code being :

17965P1557Charge Pressure Contr. Positive Deviation
any ideas guys? :zx11:

[greas-E-monkey]

Hi there charge pressure control valve faulty by the sounds of it, quite common. Its easy to replace costs about 65 pounds for a genuine one.
Thers no real way of testing it unless you have access to a main dealer computer.

Hope this helps;)

[Eshrules]

well the dealer took it into a garage yesterday, apparently the code relates to a 'hose' that has either split or come off from the VNT? something like that anyway, but this garage reckon that replacing or refixing the hose will fix the fault...not convinced that its such an easy fix myself?

[Eshrules]

thought i would keep everyone up to date on this fault as it would appear it is pretty common on these engines. after a 2nd trip to the 'mechanic' and me telling him how to do his job, he has prescribed a recon turbo. not sure why the old one has 'worn' though, as i always thought turbos were the kind of thing not to wear or just 'fail' if its failed, surely there must be a reason? or is it just one of those things?..... anyway, the dealer i got the car from i must say has been less than helpful with the whole situation, the first time it went in, a MAF sensor off another car was swapped with mine! dont know where the sense is in that, but my car was then sent out minus the 'new' maf, they had swapped it back with mine and tried to say the fault was rectified. i have asked for a copy of all invoices and written proof that an exchange has taken place as far as the turbo is concerned. caveat emptor is ringing very true right now!!

[serranta]

Hi i have the same problem as you and the same fault code. any ideas on how to sort it out i have checked and replaced some of the hoses on the turbo and they seem to be fine however the problem still remains do i need a new turbo ? :zx11:

[Eshrules]

it could be caused by the MAF sensor as well, im not sure how you can test to see if thats the fault causer, as the MAF is nothing to buy and replace compared to a recon/new turbo. they tried a different MAF on mine, wasnt happy about that but it showed it wasnt the MAF that was at fault. all i can say is,given the investigations that took place, ie new hoses & MAF sensor, the only thing left on mine was the turbo, stuck a recon on it under warranty and its been fine, plus the economy is closer to the figures i was expecting. have you actually had this into a garage? even if it does come to a turbo replacement, recons are around £250, new ones around 350/400. its the labour thats going to bite, unless you know someone who can do it for you.

[Eshrules]

just one thing that i need an answer on anybody please, when im putting my foot down in 2nd, the car boosts as normal, hesitates for a second or two and then sets off again, is this normal? im sensing not?

[serranta]

Hi i have already put a new maf sensor on the car and nothing has changed i am going to check all the pipes today and if i cant see any obvious damage to the pipes then i will have to take the turbo off and see if there is any damage to that and if so replace it thanks for advice.


it could be caused by the MAF sensor as well, im not sure how you can test to see if thats the fault causer, as the MAF is nothing to buy and replace compared to a recon/new turbo. they tried a different MAF on mine, wasnt happy about that but it showed it wasnt the MAF that was at fault. all i can say is,given the investigations that took place, ie new hoses & MAF sensor, the only thing left on mine was the turbo, stuck a recon on it under warranty and its been fine, plus the economy is closer to the figures i was expecting. have you actually had this into a garage? even if it does come to a turbo replacement, recons are around £250, new ones around 350/400. its the labour thats going to bite, unless you know someone who can do it for you.

[serranta]

Hi i have already put a new maf sensor on the car and nothing has changed i am going to check all the pipes today and if i cant see any obvious damage to the pipes then i will have to take the turbo off and see if there is any damage to that and if so replace it thanks for advice.

it could be caused by the MAF sensor as well, im not sure how you can test to see if thats the fault causer, as the MAF is nothing to buy and replace compared to a recon/new turbo. they tried a different MAF on mine, wasnt happy about that but it showed it wasnt the MAF that was at fault. all i can say is,given the investigations that took place, ie new hoses & MAF sensor, the only thing left on mine was the turbo, stuck a recon on it under warranty and its been fine, plus the economy is closer to the figures i was expecting. have you actually had this into a garage? even if it does come to a turbo replacement, recons are around £250, new ones around 350/400. its the labour thats going to bite, unless you know someone who can do it for you.

[NinjaXP]

my apologies for dragging this thread back from the grave...

i am experiencing the exact same problems, i have installed a new MAF and was wondering how complicated it would be to check the hoses from the turbo? is there a guide available? i do have a haynes manual and am probarbly going to go from that but i am newb mechanic :D willing to give it a go......any advice from anybdody please?

[NinjaXP]

hello...........??

[Eshrules]

hello...........??

?? try the search function, its dead handy ;)

checking vac hoses is simple, just look at all the braided hoses at the back of the engine bay, above the head, youll see them all there, its usually the smallest braided hoses which wear the most, so check them, make sure they're tight on the plastic 't' junctions they're attached to and the various sensors and solenoids etc. if they look worn or loose, replace them, its about £2 a meter for vac hosing.

the other culprit can sometimes be the inter cooler pipe (big plastic pipe, comes up the left hand side of the engine), if this is loose or has a pin hole it can release pressure i believe.

[ini]

If you are limping in high gears/speed with a 17965 'Boost pressure deviation' code, i would as Eshrules suggests check the N75 control tubing for leaks, check the N75 valve for blockages or bad wiring connection.

Also check the turbo vnt mechanism is working smoothly (manually try and move the actuator rod)

Check the connections from the vacuum pump, especially the brake servo.

If you have a tuning box connected, remove it, disconnect the battery for 15mins, drive around a bit, then reattach the tuning box.

In short check all 'limp mode' problems (vnt, control tubes, boost leak, vacuum leak, control valves, timing, pump wear etc.)

It is normally a vacuum/pressure leak or sticky vnt mechanism (sticky or fouled wastegate on a 90bhp)

[NinjaXP]

a big THANKYOU gents, i wanted to do this myself but i think i will just memorise your replies and take them down the garage so at least they play fair and get direct to the problem.............


:D

[golf tdi 02]

esh did you get this sorted out ?

[Eshrules]

esh did you get this sorted out ?

see below ;)


If you are limping in high gears/speed with a 17965 'Boost pressure deviation' code, i would as Eshrules suggests check the N75 control tubing for leaks, check the N75 valve for blockages or bad wiring connection.

Also check the turbo vnt mechanism is working smoothly (manually try and move the actuator rod)

Check the connections from the vacuum pump, especially the brake servo.

If you have a tuning box connected, remove it, disconnect the battery for 15mins, drive around a bit, then reattach the tuning box.

In short check all 'limp mode' problems (vnt, control tubes, boost leak, vacuum leak, control valves, timing, pump wear etc.)

It is normally a vacuum/pressure leak or sticky vnt mechanism (sticky or fouled wastegate on a 90bhp)

Ini, i could do with some advice pleesh?

background... i had a recon turbo fitted, that fixed the big limp problem, for a while. the car tends to 'pulse' through the rev count and keeps limping when approaching 80mph, although this is intermittent and its not the turbo, as you can still feel it acting, just 'limped'.

i suspect, after already having fitted a new MAF last week, that its now either the N75 valve or the VNT, i have replaced the va hoses (which i will check again tomorrow for any looseness/new holes).

my problem is... how do i check either of these, rather than blindly buying parts. i know where the N75 is and what it looks like, but im stumped about the VNT actuator :(

any advice would be appreciated and ill post up pics when i eventually find it :Blush2:

[a8 tech]

n75 can be checked by out put test on vag com,you will feel n75 pulse when it is actuator tested.Use a mitivac tester to check the vacum system and also to operate the waste gate to see if the rod is sticking and check in line the boost being applied to the wastegate

[Eshrules]

n75 can be checked by out put test on vag com,you will feel n75 pulse when it is actuator tested.Use a mitivac tester to check the vacum system and also to operate the waste gate to see if the rod is sticking and check in line the boost being applied to the wastegate

how do i do the output test mate?

and where do i get a mitivac from :Blush2:

[a8 tech]

986http://www.ross-tech.com/vag-com/tour/out_test.html http://cgi.ebay.com/ebaymotors/Mitivac-Vacuum-tester_W0QQitemZ230158799627QQcmdZViewItem http://www.ross-tech.com/vag-com/tour/adv-meas-blocks.html http://www.actron.com/product_detail.php?pid=16177

[Eshrules]

986http://www.ross-tech.com/vag-com/tour/out_test.html http://cgi.ebay.com/ebaymotors/Mitivac-Vacuum-tester_W0QQitemZ230158799627QQcmdZViewItem http://www.ross-tech.com/vag-com/tour/adv-meas-blocks.html

ok, so the last one mate, do you need a mitivac, or could you monitor the measuring blocks (specified vs requested) like you would with the MAF?

i've got the N75 test figured i think... so ill do that tomorrow

:Blush2:

[a8 tech]

You should be able to make some sense as to whats going on from the output test and the advanced measured value blocks,checking the turbo output and amount of air being read by the airmass.Good luck http://volkswagen.msk.ru/exhaust/g4/g4_exhaust_egr_syst_alh.pdf

[ini]

If you have had a new turbo fitted, and the acceleration is 'pulsing/surging' up the rev range, i would check that the vnt actuator rod/linkage (middle of the turbo body) is adjusted correctly.

If the linkage adjustment nut is set up wrong (vane angle too steep/rod too short) the turbo will develop more boost than requested under acceleration.

Try lengthening the acuator rod/linkage in very small increments (1/3 of a turn).

Alternatively fit a 'boost control' valve in parallel with the N75.

I would say that it is a dodgy N75 or VNT (internal wastegate) problem, or it could possibly be a MAP sensor fault, which you can also test with vag-com.

If your car has been remapped, overboost problems are much more likely.

[Eshrules]

You should be able to make some sense as to whats going on from the output test and the advanced measured value blocks,checking the turbo output and amount of air being read by the airmass.Good luck http://volkswagen.msk.ru/exhaust/g4/g4_exhaust_egr_syst_alh.pdf

thanks for the link ;) rather handy thank you


If you have had a new turbo fitted, and the acceleration is 'pulsing/surging' up the rev range, i would check that the vnt actuator rod/linkage (middle of the turbo body) is adjusted correctly.

If the linkage adjustment nut is set up wrong (vane angle too steep/rod too short) the turbo will develop more boost than requested under acceleration.

Try lengthening the acuator rod/linkage in very small increments (1/3 of a turn).

Alternatively fit a 'boost control' valve in parallel with the N75.

I would say that it is a dodgy N75 or VNT (internal wastegate) problem, or it could possibly be a MAP sensor fault, which you can also test with vag-com.

If your car has been remapped, overboost problems are much more likely.

the car hasnt been remapped, when i fault read it the last time, it threw up the 17965 code, which would indicate to me not to be the MAP? that's why im leaning more towards the N75/Vnt.

my main problem is that i dont know exactly where the VNT is, any chance you could point me towards it?

i ought to make it clear, that this pulsing has been present from day one, before the recon turbo was fitted. :Blush2:

[ini]

The VNT mechanism is actually inside the turbine housing, it is an 'internal' wastegate.

It is basically a ring/set of adjustable aerofoils that direct the exhaust gas around or onto the exhaust turbine, causing more or less boost,.

The linkage/actuator rod & its vacuum actator valve are connected to the middle of the turbo dumbell shape.

http://i118.photobucket.com/albums/o99/inisj/vntvolvo.jpg
Half inched from Volo site, many thanks.

When you say pulsing, what do you mean, 'how frequently' does it do it when you put your foot to the boards?

2 big surges of acceleration through the rev's?

[Eshrules]

The VNT mechanism is actually inside the turbine housing, it is an 'internal' wastegate.

It is basically a ring/set of adjustable aerofoils that direct the exhaust gas around or onto the exhaust turbine, causing more or less boost,.

The linkage/actuator rod & its vacuum actator valve are connected to the middle of the turbo dumbell shape.


Half inched from Volo site, many thanks.

When you say pulsing, what do you mean, 'how frequently' does it do it when you put your foot to the boards?

2 big surges of acceleration through the rev's?

yeah, thats exactly it, it tends to be more at lower speeds, i've noticed it mainly in 2nd and 3rd to be honest.

i think as far as finding the actuator, itll involve a feel around, im more electronics and finding problems than dirty hands work :( but ill try and see if i can find it tomorrow

i've just fault read the car, 17965 boost pressure pos deviation again.... im leaning more towards the N75 now

EDIT*********

i've just read where some guy has swapped over his N75 solenoid for the EGR solenoid, if i do this and test run the car, could i cause any damage?

[onzarob]

i've just fault read the car, 17965 boost pressure pos deviation again.... im leaning more towards the N75 now


The N75 valve is mechanical controled by vaccum, the Pressure Converter controls it, The ECU can only monitor/give faults for the pressure converter.



EDIT*********

i've just read where some guy has swapped over his N75 solenoid for the EGR solenoid, if i do this and test run the car, could i cause any damage?

Not sure if it will damage the car, but its not going to achieve anything.

Its like connecting the fuel system to the radiator, crazy!

[ini]

Yes you can swap the EGR electropneumatic valve & the N75 for testing, they are a very similar component.

Dont leave them swapped over for normal use, as they have slightly different charicteristics.

Some N75, MAF & EGR test info:

http://www.msi-motor-service.com/ximages/pg_si_0089_en_web.pdf

http://www.msi-motor-service.com/ximages/PG_SI_0017_EN_WEB.pdf

http://www.msi-motor-service.com/ximages/pg_si_0065_en_web.pdf

http://www.msi-motor-service.com/ximages/PG_SI_0076_EN_WEB.pdf

http://www.msi-motor-service.com/ximages/pg_si_0079_en_web.pdf

http://www.msi-motor-service.com/ximages/pg_si_0051_en_web.pdf

This one is for VE engines, but many of the sensors are similar:

http://pics.tdiclub.com/data/529/13523tdi-technik-eng.pdf

It sounds like you have a bit of a dead spot around 3000rpm?

[Eshrules]

Yes you can swap the EGR electropneumatic valve & the N75 for testing, they are a very similar component.

Dont leave them swapped over for normal use, as they have slightly different charicteristics.

Some N75, MAF & EGR test info:

http://www.msi-motor-service.com/ximages/pg_si_0089_en_web.pdf

http://www.msi-motor-service.com/ximages/PG_SI_0017_EN_WEB.pdf

http://www.msi-motor-service.com/ximages/pg_si_0065_en_web.pdf

http://www.msi-motor-service.com/ximages/PG_SI_0076_EN_WEB.pdf

http://www.msi-motor-service.com/ximages/pg_si_0079_en_web.pdf

http://www.msi-motor-service.com/ximages/pg_si_0051_en_web.pdf

This one is for VE engines, but many of the sensors are similar:

http://pics.tdiclub.com/data/529/13523tdi-technik-eng.pdf

It sounds like you have a bit of a dead spot around 3000rpm?

ill have a look at them in a minute, stupid work internet takes an hour to load a pdf :(

yes, it is like a dead spot, and it is around 3000rpm, its most noticeable in 4th, when approaching 80 mph, it tends not to do it if you shift early though, its more prominent when working the gears properly :(

[a8 tech]

n75 is very reliable,but the vac pipes arent and tend to split and loose pressure to the turbo,this could be confused as n75 hence mitivac test will give you the condition of the pipes and waste gate operation.n75 is controled by a duty cycle from the engine control unit and the actuator test just simiulates a duty cycle.There is a possibility that the second hand turbo is defective especially at the 3000rpm range

[Eshrules]

There is a possibility that the second hand turbo is defective especially at the 3000rpm range

PLEASE dont say that :( you would not believe the trouble i had getting it fixed in the first place, although it is supposed to have a 12 month warranty.

so lets presume then, that i check the hoses, i check the N75 and i check the VNT actuator, is there any definitive way i could tell its the turbo, other than sending it in and having it taken apart? :(

i can honestly, see this being our parting of ways for the golf and i