Hello,

I'm looking for ideas till I find some time to get to the mechanic. Curiosity and all...

Basically when my car is just started it's making really loud tractor kind of noise more like tapping I don't think I know how to describe it, but if I rev engine up, the sound kind of goes away at around 2k rpm, well most likely, because it's covered by the burning petrol sounds.

When engine gets to it's normal working temperature it turns into really silent diesel engine alike ticking sound, revving the engine up then it really kills it as if everything's ok.

I do have a code for NOx sensor (VCDS advises to replace NOx sensor)

And Incorrect flow at EVAP system

By any chance there are known cases, that one of them could cause this ? could it do some engine damage ?

When I just bought the car it was very silent, as if it had start/stop system, but it doesn't.

 

I think issue is more noticeable from inside the car, than outside.

Car: a3 8p 2.0 fsi petrol, thoughts ?

Hi I think you must be referring to the oxygen sensor this and the EVAP canister would cause the symptoms you describe, change them and it should cure your problems.

Steve.

Hopefully, well, thanks.

I have the same noise when I first start it up occasionally it’s really weird

I'm still going to the mechanic on wednesday, but if anyone curious I'm almost 100% certain, that it's cam chain.

Some symptoms are very accurate, and using flat screwdriver it seems, that the noise is coming exactly from where the cam is.

Yup tensioner failed.

41 minutes ago, gromlog said:

Yup tensioner failed.

Glad you found the fault. The screwdriver stethoscope is always my first choice for diagnosing odd noises, though a proper mechanics stethoscope is easier on the ears and skull.