Drive belt squeakage
Discussion
Hi all
My drive belt on Mk1 1.6 slips and skawks whenever i have the headlights on and the heater going whenever i set off. I tried tightening it and it worked a bit as i could have the heater on a higher setting before it started squeaking but then the belt stretched and i was back to square one. I have replaced the belt and its much tighter than the other before but it still squeaks. Is it just a case of continuing to tighten the belt until the squeaking stops? any other ideas?]
Cheers
My drive belt on Mk1 1.6 slips and skawks whenever i have the headlights on and the heater going whenever i set off. I tried tightening it and it worked a bit as i could have the heater on a higher setting before it started squeaking but then the belt stretched and i was back to square one. I have replaced the belt and its much tighter than the other before but it still squeaks. Is it just a case of continuing to tighten the belt until the squeaking stops? any other ideas?]
Cheers
I'd check that all the alternator mounting bolts are secure and that it's not just moving back to the old loose position under vibration.
Also check the pulley for excessive wear - it might not be the belt which is the slippery bit!
When you first tighten it, it should deflect a bit less than a centimetre at the middle of the top half of the belt run - pretty well tensed, but not so much that you end up breaking something elsewhere.
A new belt stretching so quickly doesn't sound likely to me unless it's being contaminated somehow (oil leak or rad hose leak?). When any of mine have started squeaking it's been because of the general condition of the rubber rather than any change in size.
Also check the pulley for excessive wear - it might not be the belt which is the slippery bit!
When you first tighten it, it should deflect a bit less than a centimetre at the middle of the top half of the belt run - pretty well tensed, but not so much that you end up breaking something elsewhere.
A new belt stretching so quickly doesn't sound likely to me unless it's being contaminated somehow (oil leak or rad hose leak?). When any of mine have started squeaking it's been because of the general condition of the rubber rather than any change in size.
The mounting bolts are tightened as per the manual so I dont think the alternator is moving. Its currently tightened so that at the top it can maybe move around 5-10mm ish. I was thinking that maybe the headlights are drawing too much power from the system making the alternator work too hard and thus the belts slips as I can turn on pretty much everything else electrical in the car without it causing the belt to slip? Could this be possible and if so what could I do to check this/stop it from happening?
Edited by fuzzyyo on Thursday 27th January 22:48
The alternator should be able to cope with headlights, wipers, washer motor, heater fans, cooling fans, heated rear screen, radio, accessories (pretty much everything electrical on the car) all on full blast without any trouble even on the coldiest s
ttiest winter day.
That said, the headlights are probably the most powerful electrical items on the car? I'm no electrician so really don't have a clue (
) but they might be the only things drawing enough current to push it over the edge.
The tension/deflection should be checked with a reasonable force being applied and you should retension the belt after running the engine for a bit after changing it as they do 'settle in' - bringing the problem straight back if it was only barely tensioned initially.
If you've ruled out the belts (checked + replaced) and don't have any noticeable headlight problems (dim/intermittent light, a bad ground somewhere) then I'd be looking at the pulleys for wear - or even damage to the alternator from over tensioning in the past.
ttiest winter day.That said, the headlights are probably the most powerful electrical items on the car? I'm no electrician so really don't have a clue (
) but they might be the only things drawing enough current to push it over the edge.The tension/deflection should be checked with a reasonable force being applied and you should retension the belt after running the engine for a bit after changing it as they do 'settle in' - bringing the problem straight back if it was only barely tensioned initially.
If you've ruled out the belts (checked + replaced) and don't have any noticeable headlight problems (dim/intermittent light, a bad ground somewhere) then I'd be looking at the pulleys for wear - or even damage to the alternator from over tensioning in the past.
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