Whirring noise from under bonnet

[shortlad]

Hi guys and girls

I've got a whiring noise coming from under the bonnet. It changes with engine revs. I first heard something about 500 miles ago and thought I was imagining things but it's got louder.

I think it could be the alternator, PAS pump or water pump. I personally think it's the alternator as the noise seems loud when you put your ear near it but that does mean I have my ear near to the engine in general.

I'm a complete non-mechanic.... any ideas/thoughts would be appreciated.

Cheers

[snorky]

I had this and it was the alternator bearings which I managed to get changed without having to buy a new alternator....

[M@H]

...yep agreed, sounds like a dry alternator bearing to me... mine only did it occaisionally and only at certain revs and is still going strong I believe.

Cheers
Matt

[shortlad]

Seems to confirm my thoughts and thanks for the tip about getting it fixed rather than getting a new one.

There's a place in my town that specialises in car electrics so will drop it in there to see if they can fix the problem.

Any idea what you paid for the fix?

Cheers

[Cruiser33]

if your a complete non-mechanic like me then take it to the V8 Centre.com in High Wycombe the guy down there really knows his stuff and is brilliant.

[manek]

Shortlad, when I had a Chimaera, I found the whirring noise was caused by the large lump of metal in the centre of the engine bay...

[duke thrust]

If you get a short length of garden hose (about a foot and a half), stick one end to your ear and waggle the other end around the engine bay and you'll be able to isolate the source of the noise. You might need an assistant to operate the throttle to the required revs to reproduce the noise.

[big_treacle]

My alternator started doing this & got louder & louder for about 2k miles before it finally went & the battery light came on. Got it refurbished for about 50 quid I think. Better to get it sorted than get stuck tho.

[shortlad]

manek said:

Shortlad, when I had a Chimaera, I found the whirring noise was caused by the large lump of metal in the centre of the engine bay...

[shortlad]

duke thrust said:

If you get a short length of garden hose (about a foot and a half), stick one end to your ear and waggle the other end around the engine bay and you'll be able to isolate the source of the noise. You might need an assistant to operate the throttle to the required revs to reproduce the noise.

I take it you are serious or I could look a bit of a nutter to my neighbours

[shortlad]

duke thrust said:

If you get a short length of garden hose (about a foot and a half), stick one end to your ear and waggle the other end around the engine bay and you'll be able to isolate the source of the noise. You might need an assistant to operate the throttle to the required revs to reproduce the noise.

I take it you are serious or I could look a bit of a nutter to my neighbours

[snorky]

mine started going on the way to it's service ! RT Racing in sheffield took the alternator off and had it done at a local engineering works for £20 while they did the service...

[M@H]

shortlad said:

duke thrust said: If you get a short length of garden hose (about a foot and a half), stick one end to your ear and waggle the other end around the engine bay and you'll be able to isolate the source of the noise. You might need an assistant to operate the throttle to the required revs to reproduce the noise. I take it you are serious or I could look a bit of a nutter to my neighbours

recognised technique

[shortlad]

Just to close this topic for any future reference....

Was the alternator and cost £45 to fix.

Many thanks for the input to my question