Serp Belt Squealing - Tried Everything

[redgriff500]

I heard a clicking noise and noticed the serp tensioner was bouncing off it's stop.

I presumed the belt had stretched and ordered another (gates) belt.

It came at the same size (1870) and as the tensioner was within 2mm of it's stop I took it back and got a 1835 which put the tensioner in the middle of it's range.

The belt squealed like a pig for the first 5 minutes of every trip (the old one never squealed)

I tried a squirt of WD40 (lasted 10 secs) so I cleaned it off with brake cleaner and tried a sticky belt dressing (lasted 10 secs) so I cleaned that off and wire brushed all the pullies - still squealed.

I tried a new tensioner - guess what - it squealed.

I tried the old belt - no squeal but again it's incredibly close to the stop.

So today I tried a longer belt - 1855 - you know what's coming... it squealed !

I don't understand how a fractionally shorter new gates belt which is under more tension would slip whilst an old longer belt doesn't.

HELP !

[Colin RedGriff]

Certainly an odd one.

The only thing I can think is that the old belt is slipping but not squealing as it's worn smooth. The new ones are squealing because they are new.

Are all the idler wheels free to rotate? Maybe a bit of lubrication in the bearings of the wheels.

[garfys v8s]

I have had this problem recently and it is still ongoing. I have changed idler pulley, tensioner , water pump and had the alternator refurbed as advised the alternator bearings gradualy dissintegrate and it gets worse. I am on my third belt now as for some reason it kept fraying on one edge and last night we found the reason for this. Some twonk had tried to lever the crankshaft pulley and bent the lip inwards. I now have to send my pulley to performance power as the 500 pulley has to be balanced. Most of my hair has been ripped out already and i still have a nagging doubt that the alternator is fubarred.

[redgriff500]

Yes all pullies seem good and free.

It's only for the first 5 mins - once warm it's quiet.

Unfortunately it's my daily driver so the majority of trips are short.