Power Failure

[Chez]

I drive an 2002 Passat Estate 130 TDI and keep suffereing intermittent power failure when on full throttle.

It feels like the turbo has been cut. I try to accelerate and there's very little there; eventually it will get up to speed but takes an age. It's even happened climbing a very steep hill in 2nd - it couldn't make it! Switch the car off and back on again and all is well (until the next time).

So off to my reliable local independent garage who diagnosed a faulty EGR valve and changed it. It's been fine for a couple of weeks but the fault has returned. My independent are at a loss and suggest a trip to the main dealer.

Any thoughts? Is the turbo the only other part that could be at fault?

[kite]

Sounds like overboosting and going into limp mode.
it could be the vanes in the turbo are stuck.
Have a search on here, there are lots of threads....

[Chez]

Thanks Kite,

I'll have a look at similar threads but in your expereince is that a new Turbo or do you know if it its repairable?

[kite]

I would start with a fault code read with vagcom, look in the vagcom section for a member near to you.
Turbo's can be cleaned out. *goes to look for link*....

Have a read

http://forums.tdiclub.com/showthread.php?t=179589&highlight=cleaning+turbo+vanes

[cazyp]

Hardly ever a new turbo. Usually one of the little 3mm vacuum pipes leaking/the N75 valve/MAP sensor/MAFF sensor (not so much) or if it is the turbo it will be the springs on the vanes coked up with carbon. Use Invotec turbo cleaner (follow the instructions) or remove and use oven cleaner..

What fault code did the garage get before they changed the EGR..?

[Chez]

Should have mentioned that there were ZERO fault codes which is why I guess the garage are stumped.

MPG is fine and the prob occurred before last MOT and it sailed throughthe emission test on first rev (apparently you get 5 goes at this test).

I'll have a look at the pipwork although not a mechanic by any stetch.

Cheers!

[cazyp]

You're looking for rubs/splits in all the braded and plastic 3mm pipes around/under the airbox and back of the engine. Replace all these with silicone hoses. Blow/suck through them to check for leaks.

Faulty MAP sensor doesn't always leave a fault code IME.

[Chez]

One of the links given above (many thanks) led me to an article that said my symptoms are typical of not driving the thing hard enough and suggested taking the revs to 3000rpm when cold and 2500 regularly there after to clean t he shoot out. I've been doing this and it's completely solved the problem. Result - and a cheap one at that. :D