Serpentine Belt

Good morning

I havn't got a lot of hair left as it is and I'am just about to pull out the last few strands. 1999 4.0 SE 67.000 miles. 1st thing in the morning the serpentine belt screams like a banshee till the engine warms up. Put on a new belt and its scream free for about a fortnight and then it starts again. So far three new belts its also had a new alternator. It does not not do this in the summer. Any idea's or should I just go bald.

when you start car do you have everthing on like heaters heated screens etc as your putting alternater under pressure. Only a guess as its only first thing .

If it uses a spring loaded tensioner like the diesel, I'd be looking at the tensioner, also worth making sure the idler pulley bearings are OK.

The tensioner is fine takes both hands to pull it back, and yes this weather the heated screens are on but it screams regardless even if I don't put them on.

yeoman said:

The tensioner is fine takes both hands to pull it back, and yes this weather the heated screens are on but it screams regardless even if I don't put them on.

Click to expand...

Just because it takes 2 hands to pull it back does not mean that it is applying the correct tension to the belt.
Could also be that the battery is loading the alternator due perhaps to a dodgy cell.

How can the alternator heated screens affect belt its the belt that turns the alternator crazy , when the belt is off check as datatek has said pully tension and all free moving pulleys for stiffness ie alternator even if new / reconditions they don't always change the bearing inside water pump and any pulley that should spin freely that runs on a bearing if not cheap/ stretched belt or not enough tension .

No one has stated the obvious. I would first check that there is no contamination on any of the surfaces the belt passes over, it only takes a spot of oil or antifreeze water to make a belt slip, also the tensioner might seem ok but is the bearing in the pulley ok?

marmitemania said:

No one has stated the obvious. I would first check that there is no contamination on any of the surfaces the belt passes over, it only takes a spot of oil or antifreeze water to make a belt slip, also the tensioner might seem ok but is the bearing in the pulley ok?

Click to expand...

Yea and that

Check the pulley on the alternator. They wear and are not always changed when an alternator is refurbished. If the slots are worn and have gone shallow, as soon as the new belt loses it's newness it will skid as the belt bottoms on the shallow grooves.

Well another new belt fitted and new tensioner, wait and see what its like tommorrow!