Whining noise

[Flat Pack]

I'm getting a strange whining noise, starts at around 2.5k RPM and gets louder with revs (not as quickly as the engine does though, so it's drowned out by about 4k). Happens when the engine is under load or just revving in neutral. It's a 'smooth' sort of noise, not a nasty grating or rasping. In fact if it had been there since I imported the car I probably wouldn't worry about it!

First noticed it a couple of months back, but it's been getting louder recently. Have changed the oil since then, no noticeable loss of power and the boost gauge still flies up to the top of the scale and sits there under load, same as it always has.

Anyone got any ideas what it could be? Not the most useful description I know, but I haven't had a chance to stick my head under the bonnet and see if it's anything really obvious yet :)

[majic79]

Turbo?

[Penfold]

If it goes away when you take your foot of the gas, I would suggest you look at the differential. That sounds like what mine was doing before it let go spectacularly at the weekend. It may be low on oil, possibly due to failure of one of the seals. easy to spot if the diff is covered in oil, just didn't get under mine for a look until it was toooooooooooo late.

[Flat Pack]

Definitely not gearbox / diff related, happens in neutral and when stopped and with foot on or off the clutch :)

I think it's a turbo, but I've not had a turbo car before and have no idea what they sound like when they're knackered ;)

[supradupra.com]

Turbos are more of a high pitched whistle and you dont tend to hear them just revving a car as they don't spin up much doing that.

Its possibly a dry bearing, ther's an idles wheel for the cam belt that can start to get noisy. Alternators are another that tend to wine too.

Power steering pumps kind of wine, does it change pitch if the wheels turned?

A stethascope is a handy tool for narrowing down this sort of thing, get them from autofactors, they come with a rod which allows you to place it on specific parts, its an interesting excersise.

[Flat Pack]

Don't think its the PS pump, not noticed it making a different sound when the steering is under load. Could be alternator or the cam belt idler (although it had a new cambelt about 10k kms ago, along with idler + hydraulic tensioner thingy).

[Flat Pack]

Was a vacuum leak, easily fixed :)

Pretty obvious as soon as I opened the bonnet...

[supradupra.com]

lol, nice easy fix then - we like those :yes: