Noisy Alternator bearings

vince · Post by **vince** » 27 Dec 2009, 23:14

Guys has anyone come across this before and is it a live with it fault?

Since the weather started to get really cold and the snow came, every time i start the car in the morning the alternator bearings sound like they are shot....(a loud chirruping noise). However literally after about 30 seconds of idle the noise is completely gone....so the engine is not yet warmed up.

Could it be anything other than the alternator bearings? Aux belt tensioner etc?

Thoughts?

HDI · Post by **HDI** » 27 Dec 2009, 23:45

Are you sure it's not a slipping belt ?

DickieG · Post by **DickieG** » 28 Dec 2009, 08:10

Are you sure the noise isn't simply due to the alternator working harder to replace the lost charge? You can test this once the noise has stopped by turning on the headlights and heated rear window to see whether it re-occurs.

jeremy · Post by **jeremy** » 28 Dec 2009, 08:32

Sounds like a noisy belt to me. You may nee a new one as the 'V's tend to wear and don't fit the grooves very well - which encourages slip.

It must be very tight - see book as to how tight and how to adjust as it varies from model to model.

DickieG · Post by **DickieG** » 28 Dec 2009, 08:38

If the belt is slipping yet is already tensioned correctly then the bottom pulley is most probably worn allowing the belt to slip due to the addtional load placed upon it by the alternator being under load.

vince · Post by **vince** » 28 Dec 2009, 09:35

Thanks for your thoughts so far guys,

The belt has been recently replaced but in any event the noise does not sound like a slipping belt.

It seems a bit warmer outside today so i will see what happens when i start it this morning......

When started first thing i always have everything turned off including blowers and rear screen de mister etc. Once running then these are switched on if necessary but the noise doesnt return......yet

Post by **RichardW** » 28 Dec 2009, 09:55

Had a noisy alternator on a BX TD - but that was a constant rumbling / whining. Got progressively worse then one weekend we went Reading - Glasgow and back,after which I was thinking it was REALLY noisy. Next day, phone call from unimpressed SWMBO "Car's stopped, won't restart". Turns out it had only lasted another 5 miles before seizing solid and stalling the engine, and with the belt still on couldn't get enough cranking speed to restart it. Was away with the belt off - exchange starter was only £65 or something (yes, even though it was seized!) - fitting it was much much harder than it needed to be though!!