Aux belt pulleys

[philheys]

Hi all,

My previous visit to Kwick Fit the guys spotted some fine steel shavings on the bottom of my engine bay, they told me could be a bearing/pulley on the aux belt that might be failing.

I also have a noise best described as a rasberry blow at exactly 1200rpm then disappears at 1300rpm I have posted this before and I have failed to find the problem, could this be related to a possible bad pully or bearing?

Anyone can advice or guide me how to check the bearings that would be great.

Thanks in advance

[cheshired5]

It's just a question of removing the belt and trying to spin the pulleys.
They should turn freely, silently and smoothly but drag slightly.
There should be no play and shouldn't be able to freewheel on their own.
Belt removal in this video and a knackered pulley for comparison at the end but if you're new to it all, I'd suggest watching it all.
https://m.youtube.com/watch?v=DLyiYnUkQuE

[philheys]

Thanks

I have watched this before, I intend to renew the belt anyway should I replace the tensioner at the same time?

Thanks

[cheshired5]

Originally Posted by philheys

I intend to renew the belt anyway should I replace the tensioner at the same time.?

It depends on your car's history.
If changes have somehow got out of sync, one part may be relatively new and still serviceable.
My alternator pulley started seizing and stressed both aux pulleys and frayed the belt so I renewed the lot.
That put the aux schedule out of sync with the timing area which was still ok for another year so was done separately.
If you're even slightly unsure, check everything and if necessary change everything.

[Brendan W]

A narrow band around 1200rpm is where my failing a/c clutch bearing made the noise. I described it as a nasal moan.

[philheys]

Thanks Brendan,

You have said before, I think I am going to tackle this job, are there any videos I can watch?

Thanks

[Brendan W]

Originally Posted by philheys

Thanks Brendan,

You have said before, I think I am going to tackle this job, are there any videos I can watch?

Thanks

Trawling youtube will throw up a few. Many are inconclusive and nothing beats whipping the belt off and checking by hand. Running the motor with it off eliminates the timing belt side.