Noisy engine when idling

[Max Ivory]

Hi

Does anyone have experience of this kind of noisy idling sound on the A3 FSI 2.0 petrol engines? I've just bought this car and don't know if its normal (car has done 109k miles) or whether something needs adjusting to make it run quieter and more smoothly (perhaps the chain tensioner?). When you first start the car cold, its quite a bit quieter but after a bit of driving when you pull up it sounds quite noisy, with a plastic-y tapping sound - basically it sounds more like a diesel engine than a petrol.

I've read that a faulty ERG valve can cause noisy idling. A VAG scan picked up such an error so could this be related?

Any advice gratefully received. Thanks all.

 

[Daveyonthemove]

I assume you checked the oil level and that's fine?
PCV would be my first guess although the idle doesn't sound rough, just noisy.

 

[Max Ivory]

Thanks Davey

Oil level is fine.

If PCV would that trigger an Engine Management Light? Mine has just come on. Stored sporadic errors on the system which my mechanic found were:

- EGR fault - sporadic
- Catalytic converter efficiency fault - sporadic

 

[Daveyonthemove]

I've not had one fail so I don't know if it would or not, but it's possible as it would be vacuum related and upset a sensor somewhere.
On mine I have removed the oil cap with the engine running and heard similar noises, but the idle is terrible until the cap is put back on.
Check the oil cap is seated correctly as it may be leaking slightly. Dipstick should be firmly in place too as that could also cause a leak.

 

[RS3 S.]

I'll bet it's the ''small'' cam chain & the tensioner on the top right hand side of the engine. ''Yes '' the main cam is belt driven but there is also a small chain & tensioner . Common fault on early tfsi engines & i had it replaced years ago on my first mk5 Golf GTI 2005 plate. As you say quiet on cold start but once warm sounds like a diesel engine.

 

[Max Ivory]

I'll bet it's the ''small'' cam chain & the tensioner on the top right hand side of the engine. ''Yes '' the main cam is belt driven but there is also a small chain & tensioner . Common fault on early tfsi engines & i had it replaced years ago on my first mk5 Golf GTI 2005 plate. As you say quiet on cold start but once warm sounds like a diesel engine.

Cheers, yes that seems likely and I've seen others mention it as a possible cause.

 

[RS3 S.]

...........if you are keeping the car it's well worth it. I managed to get it changed under the warranty i got with the car, had to push hard but in the end they did it. Was a few hundred quid if i remember correctley BUT sounds so much better after.

 

[Chris-P]

Mine sounds exactly the same. Owned over 7 years now and on 112k. I was the lead to believe the noise is created by the the high pressure injection

 

[RS3 S.]

Mine sounds exactly the same. Owned over 7 years now and on 112k. I was the lead to believe the noise is created by the the high pressure injection

.......no mate,it will be the small cam chain.