Have a MY00 turbo with 20 000 miles. Mine from new. Have developed a constant whining noise which sounds like coming from the top of the engine but can't be sure. This is because the noise seems dependant on speed. At 55 mph + its noticable. 80 + very noticeable. Dip the clutch at 80 and the the revs drop back to idle but the noise remains as loud. Same when the car is put into neutral. So it doesn't seem to be RPM or engine underload related, or gearbox underload. With the car parked and the bonnet up and and the revs brought up to 3000rpm again no noise. Any ideas please...

Thanks Jason

 

Wheel bearing?

 

Agreed, must be wheel/drive shaft related if noise is still there when car is moving but engine at idle, tricky to do but get on an empty road with a passenger, get the noise then open the windows and switch the engine off (don't turn the key enough to engage the steering lock or you may have all sorts of trouble) stick your heads out the window and see which side it's coming from, at least this will narrow it down, but agree it does sound like a wheel bearing.

Ian..

 

Thanks guys. Having read through old threads, wheel bearings do crop up. Had considered the turning off of engine and head out the window but thought the better of it at the time. If thats all it turns out to be then i'll be happy. Really hope its not a turbo bearing or the front diff. At 80mph and taking my foot off the gas and dipping the clutch.... does the turbo keep spinning at the same speed and for how long i.e. does it slow down to an idle type speed like the engine

 

Turbo will spin down very quickly, but try the engine off trick, you'll get a much more acurate indication of what is making the noise.