Tdi 110 Losing Power At High Revs!

[999mph]

hi, just bought a 2002 octavia tdi 110 estate, 77k with full dealer history etc. When driving normally it runs great, but on a few occassions when i have put the foot down, as it reaches about 3500-4000 revs, the power suddenly drops out. The car will continue to drive, and will still do 60-70mph but is just lacking power. There is no black or white smoke, no signs of coughing oil. Is this likely to be a map sensor or faulty boost valve?? Assume this is limp mode, as when i turn off and leave five minutes, car runs normally again. Any advice welcome. Hope to take to local vw/audi specialist tomorrow.

[mbames]

Most likely to be sticky vanes in the turbo. I could cause this when booting it up a hill in 3rd, virtually every time. The only real cure to this is to take the turbo off and clean it up.

Other options (less likely) are:

- faulty MAF

- faulty n75 valve

- leaking vacuum somewhere

- faulty MAP

Best bet is to stick vagcom on it and see what fault codes are logged and then take it from there. I have had many years of (fun) trying to resolve mine. I cleaned the turbo up a few months ago, but I seem to have a secondary issue, which I think is vacuum based, but I am not 100% sure on that.... more fiddling required by me. Mine just logs a normal (ish) overboost fault

17965 - Charge Pressure Control: Positive Deviation

P1557 - 35-10 - - - Intermittent

[999mph]

Most likely to be sticky vanes in the turbo. I could cause this when booting it up a hill in 3rd, virtually every time. The only real cure to this is to take the turbo off and clean it up.

Other options (less likely) are:

- faulty MAF

- faulty n75 valve

- leaking vacuum somewhere

- faulty MAP

Best bet is to stick vagcom on it and see what fault codes are logged and then take it from there. I have had many years of (fun) trying to resolve mine. I cleaned the turbo up a few months ago, but I seem to have a secondary issue, which I think is vacuum based, but I am not 100% sure on that.... more fiddling required by me. Mine just logs a normal (ish) overboost fault

17965 - Charge Pressure Control: Positive Deviation

P1557 - 35-10 - - - Intermittent

[999mph]

have been looking at other threads on this topic. Does cleaning the vanes do the job long term, or is the local vw audi guy going to tell me my turbo is knackered and take my wallet home with him???

[rwbaldwin]

Drive the car with the MAF disconnected. If the performance improves, then you have a faulty MAF.

[999mph]

drove with maf off, turbo not coming in at all. Hoping it is the map sensor. When car is in neutral, i slowly built revs up to the red line, can hear the turbo whistling away as it passes 2000, and climbing, so hears hoping.

[KenONeill]

have been looking at other threads on this topic. Does cleaning the vanes do the job long term, or is the local vw audi guy going to tell me my turbo is knackered and take my wallet home with him???

My first thought was "sticky vanes" as well. Cleaning a turbo (inside) is a specialist job that a dealership won't touch, but an "independant specialist" might well offer.

[rwbaldwin]

My first thought was "sticky vanes" as well. Cleaning a turbo (inside) is a specialist job that a dealership won't touch, but an "independant specialist" might well offer.

Take a look here for more about the problem

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/body_vnt15-turbo.html

[stevezuki]

weather permitting im stripping mine down tommorrow - got all the gaskets, praying that i dont have any stress with the oil feed pipe :S (heard they can split on removal) confused today - it revs fine in 1st/2nd/4th/5th.. but hit 3200 on a hill in third and its goodbye power hello limp mode

so tomorrow is d-day as far as sticky turbo vanes goes..

[mbames]

weather permitting im stripping mine down tommorrow - got all the gaskets, praying that i dont have any stress with the oil feed pipe :S (heard they can split on removal) confused today - it revs fine in 1st/2nd/4th/5th.. but hit 3200 on a hill in third and its goodbye power hello limp mode

so tomorrow is d-day as far as sticky turbo vanes goes..

I always found that going up hills in 3rd was the sure fire way to make mine go wrong. Since I insulation tape (ie. bodged) my vacuum brake servo pipe the car has been loads better. I might have to do a better bodge on it soon, and then replace the pipe

Good luck with getting the turbo off.... have you got a spare set of hands to help?

[stevezuki]

no its gonna be a struggle outside on the drive.. if weather looks crap- its a put off till next time..lol

[Jcb.]

For the small outlay, it might be worth running through some fuel additive (there are a few out there designed for this sort of application) in a very strong consistency (i.e a full bottle to a full tank) followed by lots of heavy right foot driving. This has been met with limited success in the past. Might not solve the problem completely but might help, and possibly worth the tenner or so the bottle of juice costs.

If limp mode comes on, stop, cycle the ignition and set off again.

Just a suggestion, but good luck!

[stevezuki]

For the small outlay, it might be worth running through some fuel additive (there are a few out there designed for this sort of application) in a very strong consistency (i.e a full bottle to a full tank) followed by lots of heavy right foot driving. This has been met with limited success in the past. Might not solve the problem completely but might help, and possibly worth the tenner or so the bottle of juice costs.

If limp mode comes on, stop, cycle the ignition and set off again.

Just a suggestion, but good luck!

yeh- ive tried gallons of diesel cleaners etc.. :( hasn't made a difference, :S ive heard on here about the induction side getting corroded and jamming :( im also gonna take the opportunity to blank the egr and give the inlet manifold a damn good clean to improve airflow etc.. but yeh- the cleaner was my first port of call- unfortunatly no joy :(

[Jcb.]

yeh- ive tried gallons of diesel cleaners etc.. :( hasn't made a difference, :S ive heard on here about the induction side getting corroded and jamming :( im also gonna take the opportunity to blank the egr and give the inlet manifold a damn good clean to improve airflow etc.. but yeh- the cleaner was my first port of call- unfortunatly no joy :(

That's a shame as it has had positive results for other sufferers of this issue. Still worth a shout for the OP though. You never know, it might not be too late yet! I run a bottle thorugh every few months now to keep on top of it. Whether it works or not? Who knows, hopefully I'll never find out and then I can deem it worthwhile

[cjb]

If you have no fault codes and no sudden drop in power at revs, my money would be on a MAF.My 110 TDI was as you describe- just a bit sluggish, and a MAF cured it.

[coilie 110]

I had the same problem a few years back and proceeded to strip turbo and clean.

Whilst I was covered in **** I dismantled the egr valve as well and soaked it diesel overnight.

Thankfully this suffering cured my problem for 2 years solid but the limp mode started to creep back.

After chatting to a VAG nut his advise was as follows,

Rev out to 2500 RPM whilst cold and at least 3000 RPM when warm.

Also use a bottle of Wynnes Diesel Injector cleaner every 4 to 6 weeks.

Works for me,

Good Luck!!

Colin... 2002 Octavia Combi 110 TDI...239'000 miles and counting!!

[mbames]

I had the same problem a few years back and proceeded to strip turbo and clean.

Whilst I was covered in **** I dismantled the egr valve as well and soaked it diesel overnight.

Thankfully this suffering cured my problem for 2 years solid but the limp mode started to creep back.

After chatting to a VAG nut his advise was as follows,

Rev out to 2500 RPM whilst cold and at least 3000 RPM when warm.

I cleaned mine out, and I have removed the EGR, and elephant mod to help too. Mine went back into limp mode 2 months after I cleaned it, but I am putting that down to vacuum issues.

I follow the same, 2500 when cold, 3000-redline when hot. I always like to boot it up at least one hill (get a few options on the way to and back from work) to make sure things are moving properly. Plus also nice to leave some black sooty in the headlights of the car behind - although this happens less, as I boot it most days!)

[stevezuki]

If you have no fault codes and no sudden drop in power at revs, my money would be on a MAF.My 110 TDI was as you describe- just a bit sluggish, and a MAF cured it.

got fault code and sudden drop in revs :( i wish it was just a simple maf replacement..

[999mph]

just got the good news from the vw specialist....the wastegate on the turbo is knackered, looking at a rebuild or a new turbo unit. Phoned the dealer i bought it off, who will thankfully stand over it and get it fixed this week.

[rwbaldwin]

just got the good news from the vw specialist....the wastegate on the turbo is knackered, looking at a rebuild or a new turbo unit. Phoned the dealer i bought it off, who will thankfully stand over it and get it fixed this week.

There is no wastegate on a VNT turbo.

[pikpilot]

just got the good news from the vw specialist....the wastegate on the turbo is knackered, looking at a rebuild or a new turbo unit. Phoned the dealer i bought it off, who will thankfully stand over it and get it fixed this week.

I believe that on the 110 tdi engine the wastegate is integral with the turbo and cannot be renewed separately. I still think your problem is a sticky vane problem so either way, push for new turbo.

[KOS]

hi, just bought a 2002 octavia tdi 110 estate, 77k with full dealer history etc. When driving normally it runs great, but on a few occassions when i have put the foot down, as it reaches about 3500-4000 revs, the power suddenly drops out. The car will continue to drive, and will still do 60-70mph but is just lacking power. There is no black or white smoke, no signs of coughing oil. Is this likely to be a map sensor or faulty boost valve?? Assume this is limp mode, as when i turn off and leave five minutes, car runs normally again. Any advice welcome. Hope to take to local vw/audi specialist tomorrow.

[KOS]

Been there done that, same year and model as yours. I came on here some months back with this problem which haunts this model, bloody VNT, I listened to all the good advice, some good folk on here, I prayed it would be anyone of the other faults listed, but knew in my heart what it was, so after spending a small fortune having a new turbo fitted no more problems since may last year, I am lucky that I know some good people at a trad country garage in suffolk, and they don't charge the earth or rip you off, I have always tried to do most jobs over the years on my cars, but this one I am glad I paid for, Had the belts done at the same time, I have heard tales of people cleaning them out, but it does not seem to work for the long term too hit and miss I felt considering I wanted to keep the car for some time as yet, Garret or vw should be shot for the pain of this bloody idea, imo. Good Luck.

[999mph]

There is no wastegate on a VNT turbo.

[stevezuki]

just removed turbo.. completely stuck solid- absolutly no movement on actuating lever now struggling to undo the three t20 torx that hold the vane assembly on.. they are up very tight and desperatly want to round out :( im surprised how well it was running considering how jammed up it is..

gonna struggle with these t20 bolts.. give it all the clean of its life and clean inlet manifold and blank egr.. might divert the oil breather too

im so looking forward to getting this back together