Squealing car on start

Meesared

So I have a 2001 VW Bora, and it has been sqealing on start for a while, just for a few seconds. Now I was told by a mechanic who looked at it before that this was a sign the alternator going, and I'm wondering if theres any truth to this. From my own research it seems to be that it could be the alternator belt either.

See I had a bit of trouble getting the car to start today, and the car was struggling to power the lights for a few minutes after starting.

So I guess I have two questions, was what the mechanic told me correct about the squealing? And also could an alternator belt going, cause the battery not to charge?

endplate

Is it a loud squeal? if so it's the alternator belt slipping. But your mechanic should have said that immediately.

07Lapierre

Yes and yes.

Meesared

endplate wrote: »

Is it a loud squeal? if so it's the alternator belt slipping. But your mechanic should have said that immediately.

Not very loud, but enough to be obvious

07Lapierre wrote: »

Yes and yes.

Which in your opinion is the cause do you think?

peasant

basically it boils down to two options

- alternator belt loose, not transferring enough power and slipping & squealing

- alternator getting tight and hard to turn causing the belt to slip & squeal

Meesared

Right so its basically take it to a garage and have them look at it?

peasant

You can easily test if the belt is tight enough:

Take the belt between thumb and forefinger and twist it. If it twists more than a quarter turn to max a half turn it's definitely not tight enough.

In most cars it can easily be tightened by lightly loosening the holding screws of the alternator and pushing/pulling the alternator out to tighten the belt more and then tighten the screws again.

If the belt isn't the problem, it's definitely garage time.

Pottler

Meesared wrote: »

Right so its basically take it to a garage and have them look at it?

Did you not say "mechanic who looked at it said alternator was on its way out"

Meesared

Pottler wrote: »

Did you not say "mechanic who looked at it said alternator was on its way out"

Yeah but he didnt check it, he just told me that from the noise it was making

burke027

Could also be the alternator pulley I reckon as the operate on a clutch system.

YellowVanMan

we have had a lot with the same problem over the years in golfs and boras. the starter getting clogged up with dust was the problem, the noise was a squeel, but a heavier squeel than a belt slipping.

Meesared

Can it be cleaned, or does it need to be replaced?

YellowVanMan

depends. we just removed them and brought them to an auto electrician. cost between 80 to 150 euro depending on whats needed, ie. bearings, contacts, and so on.

check ur belt first, the rule of thumb is to twist the belt on the longest stretch, you should be able to get about 90degree twist if it is tensioned ok.
also if you hold a piece of crayon on the ribbed side of the belt when its making noise and it stops the squeeling then its the belt.(be carefull you dont get caught in anything when doing this).
i've rarely seen the alternator making a squeeling noise, just a rough rumble when the bearings are going.
once you rule out the belt and alt then it could be the starter, but there are other units like the tensioner and water pump that also make squeels when going but they usually remain squeeling as the car is running.