Screeching sound from belt
#1
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Just got another problem with the car out of nowhere.
All of a sudden I'm getting this annoying loud screech from my belts! Aghh
Doesn't seem like a big problem, but that damn sound is louder than my stereo.
Ok, here is what I discovered. Everytime I run the a/c, fan, or anything like that the belt makes that awful noise. As soon as I turn them off, its quiet as a kitten. Do you guys think its the a/c belt? The sound also seems to happen at certain rpms, mostly 1st and 2nd gear between 1-4k rpms. As soon as I get past 4k rpms in first it stops. Or if I go WOT it will stop.
All of a sudden I'm getting this annoying loud screech from my belts! Aghh
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Doesn't seem like a big problem, but that damn sound is louder than my stereo.
Ok, here is what I discovered. Everytime I run the a/c, fan, or anything like that the belt makes that awful noise. As soon as I turn them off, its quiet as a kitten. Do you guys think its the a/c belt? The sound also seems to happen at certain rpms, mostly 1st and 2nd gear between 1-4k rpms. As soon as I get past 4k rpms in first it stops. Or if I go WOT it will stop.
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One side of the expansion mechanism that goes between the ac and mounts to the engine broke on mine - had the same symptoms. It broke right where the bolt goes into the ac. It was still tensioned but could wiggle some.
#5
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I'd first check the A/C & alternator belt for slipping. The noise seems to come when you load the belt with the A/C compressor or load the alternator with a high electrical demand. Thus the screech. The noise quiting at high RPMs is because the belt is whipping around so fast that it gets enough bite on the pullies.
That belt is supposed to be tensioned quite high - 85 lbs, which is really tight.
That belt is supposed to be tensioned quite high - 85 lbs, which is really tight.
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#9
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"Check the tension on the A/C / Alternator belt first. I had the same pb on my 968, it has to be pretty damn tight."
"I think you're supposed to have 5 mm travel on the longest section ( i.e. pull & push perpendicular to direction of travel.)"
WOW, I'm glad somebody said that... all you guys predicting the end of his A/C compressor and/or clutch were starting to worry me
Chances are it's just a stretched belt. If they are old, just replace them (A/C and PS... only $15 total or so); if not, just retension them... I'd be willing to put a fair amount of money on the squeel being the A/C belt looseness. Our friend Phil here is spot on with his info... v944god, you owe him a beer.
"I think you're supposed to have 5 mm travel on the longest section ( i.e. pull & push perpendicular to direction of travel.)"
WOW, I'm glad somebody said that... all you guys predicting the end of his A/C compressor and/or clutch were starting to worry me
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#10
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I just replaced the AC / alternator belt on both my 944S and my 951 and I have been fighting belt noise on both cars. I used Dayco belts and both seem to have streched a great deal since I installed them. 5mm of travel is TINY I did not realize they were supposed to be that tight. I was concerned with putting tooo much stress on the pullies. That helps,
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Make sure the a/c-alt belt is good (take it out and bend it, look inside the grooves fro tiny cracks) same goes for the PS belt.
Make sure the tension on these belts are tight (not too tight, i think if you press it inwards with your finger, it shouldn't excees 2cm or so), and make sure that the tensioner(s) themselves are in good condition.
On my 88 NA, the a/c-alt tensioner used to keep coming loose after a week or so of driving, replaced it for a new one ($30) and cured the problem.
Make sure the tension on these belts are tight (not too tight, i think if you press it inwards with your finger, it shouldn't excees 2cm or so), and make sure that the tensioner(s) themselves are in good condition.
On my 88 NA, the a/c-alt tensioner used to keep coming loose after a week or so of driving, replaced it for a new one ($30) and cured the problem.
#13
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i had two rollers that had seized bearings and they screeched pretty bad. but, i don't think it mattered if i had the a/c on or not.
try checking the tension first (if you already haven't). seems the easiest and most obvious place to start.
try checking the tension first (if you already haven't). seems the easiest and most obvious place to start.
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I am going to put my money on the alternator being shot. When was the last time the belts were done? This happened to me right after my belts were changed, as they were overtensioned.