peanut

I recently bought an S2 and lately I have noticed a strange noise from the underbonnet area.

Its not always there but when it starts it is definitely linked to the engine revs and its there when stationary and driving.

It sounds just like a viscous coupled fan somehow. A sort of high pitched whine/drone/whirr sound rising and falling with the engine revs but not always so noticable ?

its driving me nuts as I'm waiting for something to fail all the time. Could it be one of the belts? they were all replaced only a few thousand miles ago though?

adrian_jaye

noises are VERY difficult to diagnose on the net,

however it could sound like belts, either

1> water/power belts are loose and are screeching
2> the timing belt was done recently and was over tightened

HTH

Ade

peanut

Hi Ade
thanks for the response. If the truth be known I'm just being lazy and puting off dealing with it. I need to have someone sit in the car and drive it whilst I try to pinpoint the sound. Its amazing how sound can seem to come from the wrong place.
Its probably a slipping belt as it is not always there and not quite in sync with the revs.

livewirevoodoo

I've have the wierdest "chirping" noise since I bought the car. Its there when I start up, and stays consistent from park to drive, regardless of bieng at idle, and no matter what speed I drive at. Sounds like crickets. Has stumped 2 mechanics. But, they figure its nothing that is a safety or driveability issue. Makes me feel a lil better, but its damn annoying. Oh well....

Peanut.. visually inspect the belts for cracks, always a telltale sign. Try spraying the belts/pulleys with a little WD40 and see if that quiets it down for a bit (wouldnt suggest that for the timing belt tho..lol). That might give you a better idea if the sound is eminating from a belt.

peanut

thanks for the suggestion livewire. I'll take a look later between showers.
You'll have to throw those birds out of yours lol. The only chirping sound I've had in my 944 turned out to be the power steering shortly before it made a lot more noise and then packed up completly.
Try turning the steering wheel back and forth at rest with the engine running and see if it varies.

Maybe we should start a board for noises and send in some Mp3 's of odd noises !?

adrian_jaye

I'd be wary of spraying anykind of thing on the belts, you simply dont know how there going to react.
when belts go snap, its major buck$$$ time.

Take it in to a known Porsche dealer or indy, for a check over.

If belts are too tight or too loose they need to be sorted out.

I would hazzord a guess that it is incorrect tension on something.

HTH

Ade

livewirevoodoo

Raises a good point. While I would be completely comfortable with a quick spray of wd40 to see if it stops the noise, your mileage may vary. Best to err on the side of caution.

adrian_jaye

the thing is , I understand the idea behind it, and certainly when I've heard noises (not on belts) first idea is to try silicone lube or wd, but I can tell you times when I've knackered switches, because something reacted with something else.

With a belt I'd not want to try that in case of a major problem.

peanut

mmmmmmm I think I'd agree with you guys but the only belts I'd spray would be the alternator/waterpump and maybe the balance belt. WD40 will evapourate without residue .
As it has recently had the belts done I'm inclined to agree with your suggestions of incorrect tension. The noise does seem to come and go with temperature change and sometimes speed ( heating up of belts) Thanks for all your suggestions I'll have to take it to a dealer I guess ( 120 mile round trip ) grrrrrr

GAVMAN

Could be a worn out bearing in the alternator.

If it is the powersteering pump the pitch of the noise will vary when turning the steering from lock to lock. As mentioned earlier in this thread.

Good luck

peanut

yes a bearing looks the most likely. As soon as it stops raining I'll slacken the alternator belt tension and see if the noise goes away

fisherman

maybe the caris trying to talk to you.