Hot alternator pulley/loud squealing

[jayn5]

Hi all, recently my car (1.3 E10 liftback) has started squealing really badly. It was intermittent before, usually when pulling off on hills or parking, but now it's constant and ear piercingly loud. Ran it for 20 seconds today, switched it off, and the alternator pulley was hot to touch and water pump pulley was warm. I've been told everything from belt tensions too tight, too loose, alternator bearings gone, belts old, could be anything. Belts were done (not by me) about 2k miles ago, and look new. Not sure about the tensions, they don't seem loose when pushed down though. Currently waiting on a new tool set arriving so I've not been able to take the belts off to check the alternator by hand. 

Anyone else had this problem and can advise?

[flash22]

If it's hot, that means friction - sounds like a seized alternator, was the steering heavy - that would point to the power steering pump

[jayn5]

18 minutes ago, flash22 said:

If it's hot, that means friction - sounds like a seized alternator, was the steering heavy - that would point to the power steering pump

Steering seems ok, haven't tried to drive it since it started sounding like this though. Anyway to check for a seized alternator without taking the belts off?

[Bernard Foy]

Is it still charging the Battery??

[flash22]

A mechanics stethoscope is best, but you can use  a rod/bar or long screwdriver put the end onto the item (in this case the alternator) and put your ear on the other end with the engine running

You can then pinpoint the offending item, a bad bearing will be a deep rumble

 

If the alternator is seized, you will need a new belt and to clean up the pulleys

[Mooly]

14 hours ago, flash22 said:

If it's hot, that means friction

Could be a slipping belt I suppose. Have you visually looked to see if the alternator pulley is turning when it squeals. Also turning on headlights and heated window will add a significant load to the alternator (making it harder to turn) and can be a good way of diagnosing issues.

If you slip the alternator belt off then the pulley should be free to turn by hand.

 

 

 

[Rambler56]

If the car always starts on the ignition I would assume the alternator is working and still charging the Battery.  The squealing noise sounds like the fan belt slipping, hence the heat build up.  Does the sides of the belt have a 'glazed' appearance?

[jayn5]

21 hours ago, Rambler56 said:

If the car always starts on the ignition I would assume the alternator is working and still charging the battery.  The squealing noise sounds like the fan belt slipping, hence the heat build up.  Does the sides of the belt have a 'glazed' appearance?

Yup, does this the second the car is switched on. It's been sitting for about a month so the alternator is under a big load charging the Battery, but it's been squealing for months just more intermittent until now. Belts look intact, no cracks or visible glazing. Would the belt be too loose or too tight?

[Rambler56]

2 hours ago, jayn5 said:

Yup, does this the second the car is switched on. It's been sitting for about a month so the alternator is under a big load charging the battery, but it's been squealing for months just more intermittent until now. Belts look intact, no cracks or visible glazing. Would the belt be too loose or too tight?

Slipping belt is usually down to not being tight enough or a contaminant on the belt or pulley.  To get the correct tension I was taught to slacken off the alt mounting nut/bolt and lever the alternator out (hammer shaft) to tension the belt and tighten the nut/bolt.  To over tighten a belt is not easy unless you use a 4ft graunch bar as a lever!

[jayn5]

After some poking and proding I've actually found out it was a failing power steering pump, bearing was completely gone and it had a tonne of play, that's what was causing the massive squealing noise. The alternator tension was a bit loose, once I tightened it the pulley stopped getting hot and once I took off the power steering belt the squealing stopped. Got a replacement part on order and hope this helps someone out there!

[Cyker]

Yikes, good thing you found that in time! Well sleuthed!