D4 2.7 turbo noise?

[WhiteD3]

Often when I'm driving there's a very high pitched (not loud) noise which I can only hear when the window is down. It seems to come and go and could be there all the time but my hearing is not the greatest, especially for high pitch sounds.

When I stop the car, turn off the engine and get out I can sometimes hear the (I think) same noise which stops a minute or so after the engine is turned off.

Is this the turbo and if so, is the noise normal?

[CaverD3]

Engine or speed related?

[WhiteD3]

It seems speed related.

[Owl]

When I stop the car, turn off the engine and get out I can sometimes hear the (I think) same noise which stops a minute or so after the engine is turned off.



It's not likely to be the turbo if you hear it a minute after the engine is turned off!

[CaverD3]

Sorry much read post properly. Normal I think, mine does it too sometimes. Very high pitched sound but not very loud.

[Graeme]

They might be 2 different noises, as my 3.0 D4 is doing what I believe is ultra-sonic cleaning of the injectors after the motor is stopped. I know that some manufacturer's engines do this.

[Celtoid]

I'm with Graeme...two seperate noises.

I occasionally get a slight whine as I accelerate (3.0L D4)...assumed it was the primary turbo...which I've had replaced due to an external oil leak but the new one has the same noise....the oil leak was miniscule, so I'd wager it had nothing to do with the noise. I think it's normal.

I also get a high pitched whine after shut-down and doubt you'd hear that once the donk is up and running...so probably a different source.

My wife's Pug does the same on shut down but not as obvious...her's is petrol and no turbo. I figured fuel pump or something depressurising.....I'd never heard of self cleaning before but could be the cause, it makes sense.

I think it's all normal.

Cheers,

Kev.

[CaverD3]

I thought it might be fuel pressure releasing back into the tank or capacitors discharging?

[Graeme]

A relay clicks at the same time as the high frequency noise stops with my 3.0.

[outasight]

... or capacitors discharging?
http://img107.imageshack.us/img107/3292/791fluxnk9.jpg

:wasntme:

but I just had to ... :p