Whine from engine bay

[inyourworld]

Hi all, this is my first thread here as a new member. I've owned my '02 standard 172 for just over a month and it has developed a strange whine/drone. It is not that high pitched, but has been getting louder over the last week. I notice it most on the overdrive, and particularly at about 3900rpm/just under 60mph, and again loud just under 80mph in 5th. It is more noticeable from the driver's side of the car.

I haven't properly clocked whether the whine changes pitch with engine speed yet, and haven't tried the cluch-in test to see if it could be clutch related. Reading other posts on here I couldn't tell if others had the same or different issues hence the new post. Aux belt and related parts seem to be flagged a lot for other weird sounds, does this fit my issue? Many thanks, Chris

 

[Mike@Rentech]

aux belt idler bearing/alternator or clutch release bearing, it will be one of the I recon.

You should be able to hear it with someone revving engine stationary while you listen under bonnet.

 

[Alastair.]

wheel bearing?

 

[inyourworld]

The sound has got louder, it is more often now too. I am more swinging towards it being exhaust related as it is not a high pitched noise, it is quite resonant. It is now easy for my girlfriend to hear in the passenger seat whereas before it was only audible from the driver's side. It sounds less like it is coming from the front now too. When I was buying the car a buyer's guide I read said the exhaust was a weak spot, as was the heatshield. Anyone had issues with these that tally with my descriptions? So far as I have noticed I don't get the sound when stationary but I'll need to check that.