V50 Engine Turbo : V50 1.6Hdi (D4164T) 2010 - VNT turbo control issue ?

[Sidji]

Hi everyone,

I'm stucked with a lack of power issue that leads since monthes. No mechanics could help about (3 different ones + 2 volvo dealers - but are those mechanics anyway ?) so decided to investigate a little by myself.

So far, following was undertaken:
- Particle filter + differential pressure sensor replaced
- Fuel filter replaced
- EGR replaced & calibrated (VIDA)
- MAF replaced
- pressure test on intercooler & air inlet pipes shows no air leak
- Turbo shaft: no axial displacement, very limited radial gap (oil film thickness)
- Turbo vacuum actuator checked, new servovalve expected in few days (under delivery, but I doubt it will help...). Could not check actuator stroke though, but could that noticeably have changed with time ?
- no leak on vacuum hoses / circuit (tested with a vacuum hand pump)

VIDA doesn't show up any relevant error code anymore, but I still feel driving an old 12T Panzer fitted with a 4.5V razor engine.

Following chart may illustrate what the problem is: with 2nd gear engaged, it took 12 seconds to raise from 1080 to 3300 RPM (oh no, not an Anapurna road, just as flat as my feelings about repairing that car...).

240524-VIDA_004.jpg

Any idea / suggestion / encouragement from you guys would be warmly welcome (you may even come along with odd ideas such as 'check tyres pressure' or 'wash the car with apple juice', I wont fail to try out ! )

[iainmd]

I'm currently suffering exactly the same issue and have been through the list that you have. I've come to the conclusion that after 171k miles the vanes are either stuck, destroyed or that although the actuator looks to be working the mechanism that connects it to the vane angle mechanism has failed inside the turbo. Consequently I think replacement of the turbo is my only remaining option.

I took the output hose off the turbo, had the car constantly revved at 2000 rpm then manually activated the turbo actuator. There was no change at all in the airflow coming out of the turbo which would lead me to believe that the variable vane system has failed.

[Lightguard]

Originally Posted by Sidji

Hi everyone,

I'm stucked with a lack of power issue that leads since monthes. No mechanics could help about (3 different ones + 2 volvo dealers - but are those mechanics anyway ?) so decided to investigate a little by myself.

So far, following was undertaken:
- Particle filter + differential pressure sensor replaced
- Fuel filter replaced
- EGR replaced & calibrated (VIDA)
- MAF replaced
- pressure test on intercooler & air inlet pipes shows no air leak
- Turbo shaft: no axial displacement, very limited radial gap (oil film thickness)
- Turbo vacuum actuator checked, new servovalve expected in few days (under delivery, but I doubt it will help...). Could not check actuator stroke though, but could that noticeably have changed with time ?
- no leak on vacuum hoses / circuit (tested with a vacuum hand pump)

VIDA doesn't show up any relevant error code anymore, but I still feel driving an old 12T Panzer fitted with a 4.5V razor engine.

Following chart may illustrate what the problem is: with 2nd gear engaged, it took 12 seconds to raise from 1080 to 3300 RPM (oh no, not an Anapurna road, just as flat as my feelings about repairing that car...).

Attachment 154943

Any idea / suggestion / encouragement from you guys would be warmly welcome (you may even come along with odd ideas such as 'check tyres pressure' or 'wash the car with apple juice', I wont fail to try out ! )

Probably another test including: rpm, intake manifold pressure, egr posititon sensor & duty cycle, maf mg/stroke, intake air temperature and throttle position sensor would tell us more. Other than that, i'd check it with the MAF unplugged.

[Clan]

Originally Posted by Sidji

Hi everyone,

I'm stucked with a lack of power issue that leads since monthes. No mechanics could help about (3 different ones + 2 volvo dealers - but are those mechanics anyway ?) so decided to investigate a little by myself.

So far, following was undertaken:
- Particle filter + differential pressure sensor replaced
- Fuel filter replaced
- EGR replaced & calibrated (VIDA)
- MAF replaced
- pressure test on intercooler & air inlet pipes shows no air leak
- Turbo shaft: no axial displacement, very limited radial gap (oil film thickness)
- Turbo vacuum actuator checked, new servovalve expected in few days (under delivery, but I doubt it will help...). Could not check actuator stroke though, but could that noticeably have changed with time ?
- no leak on vacuum hoses / circuit (tested with a vacuum hand pump)

VIDA doesn't show up any relevant error code anymore, but I still feel driving an old 12T Panzer fitted with a 4.5V razor engine.

Following chart may illustrate what the problem is: with 2nd gear engaged, it took 12 seconds to raise from 1080 to 3300 RPM (oh no, not an Anapurna road, just as flat as my feelings about repairing that car...).

Attachment 154943

Any idea / suggestion / encouragement from you guys would be warmly welcome (you may even come along with odd ideas such as 'check tyres pressure' or 'wash the car with apple juice', I wont fail to try out ! )

Has the car had its regular software updates? If you have checked everything else try that it worked for me on a car which still had it's 2010 Engine software. In fact one of the 5 or so fault codes posted indicated that it was a software issue.

[iainmd]

That's me just ordered a new Garrett turbo. I'll report on my progress once fitted. After testing virtually everything, I can only deduce that the variable vane mechanism is jammed or has failed so replacement seem like the best option. The vacuum system seems fine and the actuator is moving but there is zero boost.

[Sidji]

Thanks everyone, and sorry for late acknowledgement.
@iainmd: well, your diagnostic might well be the right one. Please keep us informed, thanks !
@Lightguard: thanks for your suggestion, MAF unplugged makes no difference at all (tried that before replacing it) and unfortunately VIDA 2015 doesn't allow for more than 5 variables recordings...

[iainmd]

Originally Posted by Sidji

@iainmd: well, your diagnostic might well be the right one. Please keep us informed, thanks !

Certainly will do. I expect the new turbo to arrive next week. I hope to goodness I'm right and it fixes the issue.

[Lancee]

Originally Posted by Sidji

Thanks everyone, and sorry for late acknowledgement.
@iainmd: well, your diagnostic might well be the right one. Please keep us informed, thanks !
@Lightguard: thanks for your suggestion, MAF unplugged makes no difference at all (tried that before replacing it) and unfortunately VIDA 2015 doesn't allow for more than 5 variables recordings...

But don't acknowledge CLAN ?

[Clan]

Originally Posted by iainmd

Certainly will do. I expect the new turbo to arrive next week. I hope to goodness I'm right and it fixes the issue.

it will cost you much more by guessing you need it professionally diagnosed so it is repaired properly, Have you got the latest software for the engine ? That is very Important.

It amazes me you are happy to spend £1000 on a guess ( turbo) but wont get it diagnosed properly then repair it yourself.

[Sidji]

Originally Posted by Clan

Has the car had its regular software updates? If you have checked everything else try that it worked for me on a car which still had it's 2010 Engine software. In fact one of the 5 or so fault codes posted indicated that it was a software issue.

Thanks for the advise CLAN, but I never had any fault code related to software whatsoever. Moreover, the car has been running nicely for few years before starting gradually to loose power / torque. And despite 45+ years working in automation and control systems, I've never seen a software (nor hardware) failing gradually... but sure, I may have missed something