DSG Gearbox/flywheel/clutch noise?

[andykn]

My 2006 A3 2.0T DSG Sportback has started making an odd noise on the overrun.

Once warm (~10 mins), when accelerated, even modestly, then let off to overrun, about 2 seconds from the accelerator being released there's a short squeal, similar to when a fanbelt starts to go.

My garage said it was coming from the gearbox area and might be the flywheel, took it apart then said that although the flywheel was worn there was play on the main shaft to the gearbox and they couldn't fix DSG boxes. A gearbox specialist agreed it was gearbox, clutch or flywheel but weren't sure which, even getting a VAG specialist to listen to it. None of them could pinpoint what would be causing the noise. It's only done just over 70,000 miles, 50,000 by me since I bought it 6 years ago. Gearbox oil replaced a couple of years ago.

Anyone on here had a similar noise and know what the fault might be?

 

[andykn]

So I got the car back from a gearbox specialist and they said they though it was the flywheel/clutch assembly but weren't confident enough to recommend spending 1,500 quid changing it only to find it was the gearbox and another 4 grand needed spending.

Their recommendation was to trade it in before the noise got too bad.

 

[andykn]

So I took it to Wimbledon Audi and it turned out to be an engine breather valve (A06F 129 101 R).

On the overrun the throttle closes, a vacuum builds up drawing air through the valve, which was faulty and vibrating like a reed. After a second or so the throttle automatically opens slightly relieving the vacuum and the noise stops. It only happens when warm because the throttle doesn't fully close when the engine is cold.

 

[nluk100]

That could of been an expensive repair bill for what is probably a £5 part! Just shows that even the experts can get it wrong sometimes.

Well done Audi Wimbledon.