130 Turbo Failure After Service?

[keicar]

Hi all, I am looking for some advice. I took my 100k 2001 A4 (B6) TDi 130 to an independent for a service and cam belt (it had not been replaced for 5 years @ 60k).

On picking the vehicle up I noticed a distinct lack of power and a 'whirring noise'.

I took it straight back, and was told it was a split pipe. This was replaced and the fault still remained and am now being told the turbo has gone. The vehicle was fine when I took it in and I feel its a my word against them situation.

Two questions really 1) is the turbo likely to fail at service/cam belt replacement 2)Is there something obvious that has been missed on re-assembly?

Any help gratefully accepted......Thanks in advance!

[Crasher]

They would have to do something pretty stupid to damage the turbo so I suspect all it that is wrong is a vacuum leak around the N75 valve area, right where you are working when doing a cam belt. The whirring noise is hopefully belt noise.

[keicar]

Thanks for reply, where is the N75 area?

[Crasher]

Sorry, the N75 is the valve that controls the turbo vanes and this is located down the side of the engine in front of the turbo alongside the timing belt area. One quick test, disconnect the small 3-mm vacuum hose from the servo feed pipe up at the plenum chamber bulkhead (take care, you could snap it off) and suck on the 3-mm hose you take off. You should not be able to suck air though this hose, if you can a hose/pipe is off further along or split/rubbed through.

[rollapig]

When i had my cam belt changed it snapped after 3 days !!!The garage were really good and sorted it out but when i got it back it had a whirring noise and it turned out to be the cam belt being over tensioned which is probably what they done in the first place so it might be worth the question to them ,it could save you a lot of hassle!

[Crasher]

The noise could be belt tension, the car probably has the extremely irritating hydraulic (rather than the later friction type) cam belt tensioner and I often see (hear) these set too tight. They take ages to get right, a combination of a perfect 4-mm gap on the tensioner arm and the locking plate/pin dropping straight in. Most people don’t bother as it can add half an hour to the job. The later friction tensioner takes a fraction of the time to set.

[keicar]

The noise could be belt tension, the car probably has the extremely irritating hydraulic (rather than the later friction type) cam belt tensioner and I often see (hear) these set too tight. They take ages to get right, a combination of a perfect 4-mm gap on the tensioner arm and the locking plate/pin dropping straight in. Most people don’t bother as it can add half an hour to the job. The later friction tensioner takes a fraction of the time to set.

Cheers crasher! gonna bring the car home today, the chap is adamant that the turbo has gone and the whirring noise is still there, lost all confidence in him dont think he's done anymore work on it. I'm not a complete duffer have changed water pumps and cam belts on Vauxhalls before, would it be possible for me to access the cam belt tensioner and N75 valve myself to check?

I cant believe the turbo has failed as it was running just fine when I took the vehicle in and no noise whatsoever, my first impression of the noise was that it was belt noise.

Thanks in advance.

[Crasher]

Yes but you need to pull the front end back into the service position, two 100-mm long M8 bolts will allow you to do this.

[jesliemh]

hi there, this is regarding with the forum above you've made before, could i ask some of your opinion and help me things clear? i have an a4 saloon 1.9 tdi, 100bhp, 04 reg., have done major service and timing belt kit with waterpump replacement yesterday from an independent garage, when i went home and traveled about 60k, it seems everythings ok, i decided to open the bonnent to check all the works done with the engine running idle, i heard some whizzing sound, (sort of friction) but not too loud, obviously from the timing belt housing, but when i closed the bonnet, i cant bearly hear it, now my question is, is this a normal sound for a new timing belt? is this sound will disappear when it stretched as time goes by? or is this not a good sign of quality work? i hope you can help me with your opinion because i know your a good and experienced audi mechanic, as ive always read all your forums, many thanks and all the best...