Whirring noise

[A4Steve]

I am getting a whirring type of noise coming from the engine bay of my S3 when switched off. It continues for three or four min's then stops. I only noticed this today when I stopped to check the oil. Can someone explain if this is normal, and if so, what it is that's still working in there /ubbthreads/images/graemlins/confused.gif

Cheers
Roger

 

[Inigo]

Yep its normal....its some sort of post-timer - i've had it explained to me enough times I really should have remembered by now. Basically, it keeps cooling your engine and turbo once you've powered down. A very valuable addition to any turbo engine - although I still try and let mine idle for a while after a fast session.

Inigo

 

[audi_girl]

Yeah, I think it's either pumping water or oil around to cool everything down.

I usually try to drive "sedately" for the last couple of minutes as well !

 

[Jon]

The other comments pretty much answer the question but the purpose of it is to keep the oil etc circulating once you turn off the engine etc, this prevents oil carbonising in the turbo's oilways and bearings after a hard drive, if this happens the flow to the bearings is reduced and will ultimately result in a blown turbo due to the oilways blocking.

You used to be able to buy things called a Turbo timer which used to do a similar thing but just kept the car idling for 5\10\15 minutes after you finished your drive.

I also let the car idle for 5 mins or so and do the last few miles in normal driving mode not "maximum attack" /ubbthreads/images/graemlins/smile.gif to let everything cool etc.

Jon.

 

[AlexStanley]

I've always wondered, actually, whether the underside is at all protected from such unavoidable scrapes etc. - does anyone know?

 

[melman]

There is a plastic undershield but mine is pretty damaged and was told once that if I replaced it, it would only happen again very quickly!