Squeeeling on start up

Jshodgson · Unread post by **Jshodgson** » 06 Jul 2006, 21:14

Hi all

when I started my Xantia today there was a really bad squealing. The STOP light stayed on for much longer than usual as did the battery light. I drove to work (21 miles) and the squealing only stopped when I went above 30mph. Even when hot at the end of the journey it still squealed when idling.

I looked at the alternator and belt and the belt is very slack (moves about 10-15mm) the alternator also moves slightly. I tried to tighten the belt but some stupid bugger has rounded the allen key nut on the adjuster so I can't. I tried some mole grips but with no joy.

I then slackened the upper alternator mounting nut and could move the entire thing!! I was expecting a mounting point at the bottom aswell?!?!?!?

I tried to rotate the alternator to tighten the belt and see if that stopped the noise but I think with the force of the belt it just moved as the squealing continued.

Any ideas or suggestions on what to do next?????????????

citronut · Unread post by **citronut** » 06 Jul 2006, 22:02

sounds like a bolt is missing,
regards malcolm

Unread post by **Peter.N.** » 06 Jul 2006, 22:28

Yep, and the squealing willl undoubtably be the belt slipping.

Jshodgson · Unread post by **Jshodgson** » 06 Jul 2006, 23:21

any suggestions for adjusting the rounded nut?

James.UK · Unread post by **James.UK** » 06 Jul 2006, 23:30

Replace it.. If you cant get it undone take it to your local garage, they will do it for a small charge..

Jshodgson · Unread post by **Jshodgson** » 08 Jul 2006, 12:06

I have used 4 new bolts (found that there were others missing!) and now the belt is much firmer and does not squeal. As the adjuster is unuseable at the moment I could not fine tune the tension in the belt and I am left with about 3-5mm of movement when I press it.

Is this too tight?

Are there any potential problems if the belt is too tight?

AndersDK · Unread post by **AndersDK** » 08 Jul 2006, 18:45

The alternator shaft bearing is designed for this during its service life. I'd say there is a larger risc the idler (tensioner) wheel bearing will wear out first - if the belt is too tight.
I doubt you've got it too tight - unless you are a blacksmith 8)
Enjoy your work - and your car

kip · Unread post by **kip** » 11 Jul 2006, 00:17

I had a noise that I thought was the hydraulic pump. It also caused some squealing on startup.
Eventualy it turned out to be the Idler.
The whole thing disintergrated with an imbaressing amount of smoke in peak hour traffic.

I was able to replace the bearing with a $5 bearing from the local bearing supply shop. That and a new belt.

Jshodgson · Unread post by **Jshodgson** » 12 Jul 2006, 08:03

After tightening the belt there is still a small squeal on start up which goes once the enginge has been revved. After my previous diagnosis and work what should I check next?

citronut · Unread post by **citronut** » 12 Jul 2006, 08:34

adjust the belt tention up a bit more as these ribbed belts need to be very tight compared to the old V belts,you will be suprised how tight they have to be,but only adjust a little at a time until it stops squeeking
regards malcolm

rmunns · Unread post by **rmunns** » 15 Jul 2006, 15:04

The easiest solution I've found is WD40. Instant cure!

Jshodgson · Unread post by **Jshodgson** » 16 Jul 2006, 20:17

roger what did yoou do with wd40?

AndersDK · Unread post by **AndersDK** » 16 Jul 2006, 21:23

Jshodgson wrote:roger what did yoou do with wd40?

Bet he sprayed it on the belt. Works a treat - for a week or so

The idea is to treaten the belt rubber to make it softer and then grip better. That prevents the belt from squealing.
Better still is to use a silicone spray - the type used for door rubber lists etc. Makes the rubber surface much softer.

In other words - if the spraying instantly helps - you need to have the belt tightened a bit further.