2002 Golf TDI 130, limp Mode, please help

[wasabi]

Hey Guys,

Wondered if anyone could shed any light on my situation.

My 130 bhp tdi works great the majority of the time, the turbo works all the way until it is asked to accelerate hard from 2000 rpm to around 3500 + in 4th - 6th gear.

Once this point is reached the car will put itself into limp mode. I can turn the car off and on again (whilst still moving) and the performance is back until i will push it again past 3500 revs and it will repeat the process. I must stress the turbo does pull like a train but dies at a certain stress level.

I have replaced the N75 valve to no avail, have looked at replacing the MAF but my problem sounds different to those highlited here.

The car does run a bit gruff on occassion, which made me wonder if the MAF did need replacing.

I know these turbos get sticky vains, and the internal waste gates get clogged and stick resulting in an over boost reading, but im reluctant to shell out on a new turbo when it clearly works.

Any help would be so greatly appreciated (have had a few experiences of the car going into limp mode whilst over taking - not fun)

[smoker]

Does sound like a turbo fault had the same problem it was caused by the vanes on the turbo sticking. From what I understand they get stuck causing the boost pressure to get too high at high revs as you probably know. I should imagine working the actuator arm or ar worse removing the turbo and cleaning the vanes etc. should fix it. In my case there was a fault code logged for excessive turbo pressure.

If you want to be sure you could plumb in a pressure gauge..i think you will find the pressure going over 2 bar when the engine shuts down which is way too high. You could also check the vacuum signal to the actuator ..should go from high vacuum at idle/low speed to atmospheric pressure if the control system is working ok.

[wasabi]

Hey,

All i know is what i have picked up over the internet,

How much work is involved in cleaning this out. Most people say its a case of getting a new turbo. I have tried a can of the 10k into the turbo inlet pipe which had a bit of an effect but not enough. Also the internal waste gate does get sooted up and stick open. If you really hammer the car through the gears it wont go into limp mode. Which makes it seem like the waste gate is sticking and when really pushed it is under to much pressure not to move.

Its a real pain in the *** and far to common, i have heard of this type of incident happening on cars with as little as 16k on the clock.

Any more info anyone has on the sticky veins issue is most welcome, and any info in general on this issue.

[smoker]

I saw an excellent write up somewhere on cleaning out the vnt mechanism on www.tdiclub.com i think. The guy said it took him 3 hrs all together to remove and replace the turbo....took me longer the first time but i removed the inlet manifold and you don't need to do this. Not too bad a job once the driveshaft is out of the way.

If you get the car on a ramp you should be able to see the vnt actuator...with the engine running remove and replace the vacuum hose and see how far the lever moves, then with the hose off see if you can push the rod back further with your thumb. .If it's not returning to it's stop it needs working to free it off.

[wasabi]

Sounds good, have you had this similar problem, and did this solve it.

Im guessing this isnt the same as the sticky veins issue?

[Eshrules]

Sounds good, have you had this similar problem, and did this solve it.

Im guessing this isnt the same as the sticky veins issue?

nope, the vines are the actual blades of the turbo i believe... the VNT mechanism is a different part of the turbo, i found an excellent link the other day, let me find it and ill post it up here for you

definitley sounds like your turbo to me, i managed to get a recon turbo out of my dealer (warranty repair) but if it were me, id get the turbo off and give each component a good clean... 9/10 the turbo isn't knackerd, just filthy and in need of a bit of TLC....ill find that link

[Eshrules]

http://www.technologie-entwicklung.de/Gasturbinen/VNT15-Turbo/vnt15-turbo.html

try that, its a guy who messes about with turbos from what i can see, but is a good visual of how the turbo breaks down into its different components

[wasabi]

Esh you are a star, im going to contact my buddy the mechanic and in exchange for bottled refreshments im sure he will lend a hand.

Cheers mate, ill post the results when im done.

[Eshrules]

Esh you are a star, im going to contact my buddy the mechanic and in exchange for bottled refreshments im sure he will lend a hand.

Cheers mate, ill post the results when im done.

good lad! i tell you what would be REALLY helpful, when you and you're mechanic are doing what ever you do... if you could take pictures along the way and post them up here for other peoples reference....

then if your feeling really helpful, you could talk us through what you did.... would be much appreciated i can say that much

[gttdi]

Well folks,

Just stumbled across this thread and I have a very similar problem with my '02 Golf GT TDI 130, it goes like the clappers til it reaches 2500 revs in 3rd/4th gear then hits "limp home" mode or else til I hit approx. 85 mph in top gear... at which point it wouldn't pull the pants off a hooker until the engine is turned off and turned back on, not much fun as you can imagine when overtaking and it trips out .... Also means I've been smoked on motorways by just about everything you can think of including Daewoo Matiz and most recently a Scooter... Oh the shame!!!

Just wondering did you clean out your turbo, or take it off or what?? Heard people say it could be N 75 valve, sticky wastegate, stick veins, etc and just wondering had any of you any luck with yours or get it sorted????

Cheers

GT