Audi Tdi Turbo Failure?

[Aprisa]

Need some advice on an engine fault.

Wifes A3 Tdi has slowly reduced in power and now seems as if there is no real turbo boost at all, the engine stil runs sweet enough and has no abnormal sounds.

I have been told that ther are sometimes problems with the turbo blades? is this a servicable item and would it produce the symptoms as above. Engine has done 56K.

Any experiences with this problem?
Nick

>>> Edited by Aprisa on Monday 22 March 09:05

[Mr2Mike]

It's unlikely to be a turbo fault, and they are not really user servicable. Turbo failure would involve a new/reconditoned turbo and lots of £££'s.

I would check the wastegate acutator and the pipework connecting to it. A friend with an Ibiza using the VAG 1.9TDi had lack of boost problems which turned out to be the actuator pipe which had become kinked. This prevented the air in the actuator from being released which kept the wastegate fully open all the time.

[annodomini2]

also check the injection advance, can have the same effect.

[stevieturbo]

Could be as simple as an air leak. Cheack all rubber pipes and joints
Check the one that goes into the inlet manifold, Ive seen the rubber split there before..

[Sparks]

Also Check the AAM. The petrol 1.8 suffers from problems with this, as does the Saab 2.2 TiD.

Often shows as a distinct tail off after 3000rpm, but mine (a saab) just got very slugish all round.

HTH

Sparks

[aprisa]

Thanks all
/ignorance head

AAM?

ignorance head
Nick

[margo]

Check the engine electrical connections are solid,particularly the intake sensor which seems vulnerable, if the engine management is not receiving all the inputs it will go into 'limp home' mode, cutting the boost. For some strange reason this doesn't usually result in a warning light

(Ours arrived like this, the dealership having forgotten to plug something in after a service )

[dougc]

margo said:

intake sensor which seems vulnerable,

This was the trouble with my dad's 1.9Tdi at about the same mileage (60k IIRC). It just got progressively slower and more 'laggy' until a quick trip to the dealers got it sorted.

[stone]

Could well be the air flow sensor. I had this on my A4 tdi, Audi replaced it as a goodwill gesture when the car was 4 years old - 70000 miles - I think it is a recognised problem and Audi tend to be fairly good at putting right.

[Mr2Mike]

stone said:

Could well be the air flow sensor. I had this on my A4 tdi, Audi replaced it as a goodwill gesture when the car was 4 years old - 70000 miles - I think it is a recognised problem and Audi tend to be fairly good at putting right.

Good point, my old man works in a garage and has said he sees a *lot* of MAF sensor failures on the TDi VAG engines. Not exactly cheap either.

[Sparks]

aprisa said:

Thanks all /ignorance head AAM? ignorance head Nick

It shouild have been AMM anyway.

Air Mass Meter. It's what Saab call the airflow sensor other people are talking about.

Sorry, was a bit of a quick post and forgot to explain myself or type it right

Sparks

>> Edited by Sparks on Tuesday 23 March 19:58

[aprisa]

Many thanks to the PH Knowledge Base!

It was the Air Mass Meter, and because I was pre-armed with your experiences Audi were obliged to go most of the way towards the total cost which would have been £400.

Cheers Guys
Nick

[stevieturbo]

As far as I am aware, you can buy the VAF Airflow meters for around £85.

Or the same airflow meter is fitted to some mercedes commercial vehicles, and can be bought for under £50.

Dont have any part numbers, but have been told by various people in the trade.