engine trouble code 17965 - turbo dying? HELP!!

[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/...r_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/...r_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.

[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.


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/xim...089_en_web.pdf

http://www.msi-motor-service.com/xim...017_EN_WEB.pdf

http://www.msi-motor-service.com/xim...065_en_web.pdf

http://www.msi-motor-service.com/xim...076_EN_WEB.pdf

http://www.msi-motor-service.com/xim...079_en_web.pdf

http://www.msi-motor-service.com/xim...051_en_web.pdf

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

http://pics.tdiclub.com/data/529/135...echnik-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/xim...089_en_web.pdf

http://www.msi-motor-service.com/xim...017_EN_WEB.pdf

http://www.msi-motor-service.com/xim...065_en_web.pdf

http://www.msi-motor-service.com/xim...076_EN_WEB.pdf

http://www.msi-motor-service.com/xim...079_en_web.pdf

http://www.msi-motor-service.com/xim...051_en_web.pdf

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

http://pics.tdiclub.com/data/529/135...echnik-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