Squealing Noise-Alternator?

[Tim_021113]

I have a 2002 2.3 Zetec Petrol Auto.  About a year ago it developed a squealing noise when cold, so the aux drive belt was replaced.  The noise came back in February and the belt tensioner was replaced.  All well until about a month ago when the noise came back and is now worse than ever and is also constant.  It used to go away once the engine got warmed up, but not anymore.  My local garage reckon its belt and tensioner again but I am not convinced.

 

Having read through a lot of threads and FAQs (especially the ones from littledaz), it looks like a number of people have fixed their noise problem by replacing the alternator pulley.  But...that seems to be on TDIs where the pulley is meant to freewheel in one direction and not the other.

 

So, does the pulley issue also affect petrol cars and if so can the pulley be tested and replaced the same way as on the diesels?

[chrispb123456]

I'm not sure if the 2.3 has a clutch type pulley or the solid type, but also check your aircon pump is not seizing up.

[chromedome]

I think only diesels with the Dual Mass Flywheel had the clutch type pulley but I stand to be corrected............................

 

Like chrisb12345 mentioned check the compressor. Turn off the a/c and see if the squealing stops. 

Edited October 23, 2014 by chromedome

[gregers]

if it turns out to be the clutch plate on the aircon compressor,it can be replaced in situ.

[Tim_021113]

Thanks for all the replies.  The noise is present whether the aircon is on or off, but I'll check the compressor anyway.  Time to fish out the trolley jack and axle stands...

[seanwhu]

Have you changed the idler pulley as well.  I did both the tensioner and idler pulley on my 2.3 and all was ok after that.

 

Good luck

[Tim_021113]

Dug out the axle stands today and had a look.  I ran the engine for a short time with the drive belt loose and the noise disappeared.  Got the belt back on and ran the engine and the noise was back straight away.  For a while I was convinced the source was the air con compressor, but then I sprayed some oil onto the power steering pump between the pulley and the body, and immediately the noise went away.  So at the moment that looks to be the culprit.

[chromedome]

Hopefully a drop of oli may cure it. Just a thought, is the under tray fitted. If not the power steering pump is one of the first victims of rain which can cause momentary steering failure.

[Tim_021113]

The oil hasn't cured it, but at least I know what I'm dealing with now.  The under tray is fitted so happily everything wasn't covered in gunge. Going back to my original question about the alternator, with the belt slackened off, the pulley spins freely in both directions so it looks like the clutch system is just a diesel thing.  Thanks again for all the replies, greatly appreciated.

[sparky Paul]

Solid alternator pulley on the 2.3 petrol.

 

If the noise sounds like demented budgies and the idler hasn't been replaced, that will almost certainly be the culprit.

 

Usually spraying a bit of oil or water about cures the problem for a short while.

[Tim_021113]

sparky Paul - the noise goes away for a short time if I spray oil either onto the belt, or into the body of the power steering pump.  Do you think both of those still point to the idler being shot?

[sparky Paul]

It doesn't need much of a mist of oil getting onto the belt to shut the noise up for a bit. It's impossible to guarantee that will be it, but these noises from the belt on the 2.3 are almost always the tensioner and/or idler pulley.

 

The idler is easy enough to replace, and it's cheap compared to the tensioner - I would guess about

[Tim_021113]

The belt, idler and tensioner have now been replaced.  The tensioner was replaced under warranty because it was less than a year old.  And now, all is quiet again at last.  So I'll see how it goes and report back in a few months....