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Fan Belt
Furious D - 7/6/07 at 07:20 AM

Morning all

I am pretty sure the fan belt has started slipping, however i say pretty sure because.

I has happened two or three times in the last maybe 4 or 5 trips out and not at all on some of those trips. Bought the Tiger into work this morning to check and see if any strange noises (got a big drive coming up on Sunday) and everything was going fine until i was stuck in traffic and the engine was getting hot and a belt (fan) slipped. Only slightly and only in first as pulling away. The thing is, why does it only do it when the car is hot ie: above 90C?

The rest of the time it was fine. Coughing and farting a little bit when it got hot too but other than that ok.

I really do not want to break down at the weekend i have been looking forward to this trip out and there are plenty of other cars coming.

Should i:
A: Leave it
B: Tighten it
C: Get a new one (not sure if i have the time to fit though

Cheers Guys
D

Macbeast - 7/6/07 at 07:34 AM

B or C. Should take about 10 minutes

David Jenkins - 7/6/07 at 07:40 AM

No real answer, without looking at the belt!

What I would do is:

Have a critical look at the belt - is it looking frayed, shiny, cracking, etc. Compare with a new one, which is usually black, dull and feels 'rubbery'.

Check the pulleys - are they dirty, with belt rubber or other rubbish stuck in the grooves? If so, clean them.

Check the tension - your Haynes manual should tell you how much deflection is required in the longest run between pulleys, when you push with your thumb.

If everything else seems OK, I'd change the belt - they're cheap, changing one usually only takes 20 - 30 minutes max, and it'll be a lot more 'grippy' than one that's been on the car a while. The old belt may be slackening when hot (which may be the answer to your other question!)



HTH,
David

neilj37 - 7/6/07 at 07:44 AM

Also check to see if there is any powdery deposits around as this is a sign that the belt is being worn and there could be some misalignment on the pulleys or the belt is too tight.

02GF74 - 7/6/07 at 10:14 AM

quote:
Originally posted by Furious D
i was stuck in traffic and the engine was getting hot and a belt (fan) slipped. Only slightly and only in first as pulling away.


wot you on about? is it timing belt? or belt for water pump/alternator/crank ???

is it v-belt or flat grooved belt?

how do you know it is slipping - usually you can hear them screach a lot of the time.

is this a new occurence or has it alswys happened, if new, was anything changed?

things to do/check, not necessarily in this order

1. condition of belt.
2, security of nuts bolts
3. water pump bearing
4. alternator bearing
5. condtion of pulleys - are they worn?
6. suitability of pulleys - are they the right wdith for belt? if too wide the belt will not ride on side of the V so you won't get right tension
7. belt tension?
8. replace belt and repost with more information.