[Corsa C] Whirring/whining sound from engine bay

[Aaron]

Trying to work it out at the moment. Sounds like its coming from the middle of the bay bear throttle bottle and alt. Video here Dropbox - Error


Hoping its nothing major. Just trying to work out what it is. Didn't seem as loud today, wondering if it somehow related to wet weather and recent new exhaust change.

[Aaron]

Whirring noise during driving goes when clutch pedal is pressed down. When I use clutch it fades out over a second. Stationary whirring is constant regardless of clutch. Follows rev also. Still trying to work it out.

[small9918]

Sounds like one of the pulleys on the alt belt check to see if any are loose.

[Aaron]

Thanks small, going to a mates in York tommorow who's better than me with engines but I was suspecting it could be something like this, we will take a look and report back

[walksall]

From what you say, it would pay to check the gearbox oil level.

Regards.

[Aaron]

Mate looked at it and feels certain its the alt. I'll check online see how easy is it to check gear box oil

[Taurus]

I can't hear it on the video clip, but if the guy thinks it's the alternator then bear in mind they can run noisy for ages and work fine, or they can decide to die on you just to prove Sod's Law still works. Use a stethoscope to check - they're cheap and are one of the best bits of diagnostic kit you can have in your kit.

To check the gearbox level - there's a level plug in the side of the gearbox casing by the n/s driveshaft. The car needs to be level - which is easy on a lift but a bit trickier when you have to do it at home since it's easier to remove the n/s/f wheel to get at the plug (and then the car isn't level.

One trick is to jack it up just high enough to remove the wheel and then the plug, add some oil via the filler (at the top) until it shows at the level plug - the gearbox is now overfull of course - so you lower the jack to get the hub at the same height as when the wheel is fitted, this allows the excess oil to flow from the level hole. When it stops flowing refit the plug, jack up again, refit wheel and lower the car. This ensure the level is correct and makes access to the level plug easier.

Usual H&S noises re. jacks and axles stands of course.

[Aaron]

I had my head in the bay and I feel its almost certain to be the alt, the noise comes around the back of the plastic/motor related stuff near top of the engine, no noise as such from the alt belt on block but as you put head down there you can hear It coming from the alt. The above description is hard to explain, but what I mean is, that the appears to come from alt at the side, and the noise itself doesn't come through the block as its in way but comes around the back. I've had my ears on other items and I can hear their own noises which are different.

For sake of £20 I'm going to replace it as the noise is doing my tits in, if it does turn out to be something else then I will buy the stethoscope and take it from there, thanks again.

[Aaron]

Resolved - was alternator

Sorted for £18, well happy.