Audi a3 8V weird noise under boost

[ppe1700]

I have a 2016 Audi A3 (8V) 1.8 TFSI. I've had the car since brand new. The car is still under warranty which runs out next month.

Last Friday, I am getting a noise while driving. Initially I thought it was the gearbox issue had occurred again (warranty for thrust bearing apparently). However since Friday the noise has now changed to a wooshing noise and I think it's the turbo. I'll do my best to describe this... As the turbo begins making boost, the noise sounds like the turbo slowing down then spooling up again. It sounds like a wooshing but more like one of those old whistles you got when you were a kid (not quite a kazoo but similar, except has a thing that spins when you blow). As well as wooshing it sounds like flapping. Because the noise isnt constant like a turbo, it sounds like the turbo starts speeding up and then somehow is abruptly slowed and then it starts spooling up and this repeats while I am accelerating. Although, I thought if this was the turbo changing speed then the power delivery would have been affected.. I havent noticed any drop in performance or stuttering. The noise also does not happen when the engine is at temperature but not been running for long, so say for the first 20 minutes of driving I do not hear this noise at all. The noise happens around the mid RPM range and during boost.

I said I thought it was the gearbox initially because the noise happened during acceleration and just after the car changed gear.. But I found that if I put it in manual mode and use the brake and accelerator then the noise will happen.

I tried to google for any known turbo issue but reading those descriptions I dont think they are the same. I don't have stuttering or anything like that - well I am almost sure. On the way to work this morning I was trying to figure this noise out and may be there was shuddering, but I couldnt tell if there were just some tiny bumps in the road. And I can't put my foot flat to the floor because of the button under the peddle which downshifts and the RPM goes too high for the noise.

Wanted to post here and ask the forum in case some experts know about it. I am reluctant to go to Audi because every time I have taken the car to them with a problem, they have it for a day and then tell me they can't find anything wrong. Even for the gearbox and I spent weeks getting that one sorted. So I doubt I'll have much luck with them unless I know what to tell them.

Any help appreciated

[cliffcoggin]

Tony.

No matter what the cause you should get the fault registered with Audi before the guarantee runs out. Even if Audi then prevaricate about fixing it they will not be able to deny that it occurred during the guarantee period.

For what it's worth I favour the turbo as the culprit, an expensive repair job and not something you would want to pay for from your own pocket.

[ppe1700]

Thanks for the advice Cliff. Unfortunately they're pretty incompetent. When they delivered the car to me, the tracking was knocked out. When I reported there was something up with the steering, they said they checked and there was nothing wrong. A 2nd check confirmed the tracking out and a charge to me of $150 to fix it. When they fixed the gearbox they caused an issue with the suspension causing it to creak like an old bed. They couldnt find anything wrong for ages with that one and took two goes to fix it.

May I ask - is it normal for the dealer to inflate the tyres to 46psi? Seems a bit high to me. And we had bad wet weather at the time. Made the traction very bad and steering very light. The next day I checked and let the tyres down to 34.

[cliffcoggin]

Incompetent or not, the dealer is responsible for the warranty until it expires. Whether that means he has to do the work or only pay you for getting it done by somebody else under Australian law I have no idea, but if you don't complain now he will always have the excuse that the fault arose after the warranty ran out.