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Old 09-24-2016, 01:12 PM   #1
1969c10joe
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diagnose screech

I have a screech when i rev engine it happens in neutral and in gear only in second my first gear is granny. it is not a belt squeal. clutch fan seems a little tight but its doesnt sound like an airplane. also throttle response seems to lag a bit it only does it when rpm is low and i give it the gas hard.I wouldnt worry but i hope to motor across country and i know a sticky clutch fan robs power lowers mpg
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Old 09-24-2016, 01:27 PM   #2
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Re: diagnose screech

It's your fan belt!
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Old 09-24-2016, 01:40 PM   #3
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Re: diagnose screech

...or power steering. But it sure sounds like a belt. Why do you say "It is not a belt squeal"?
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Old 09-24-2016, 01:59 PM   #4
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Re: diagnose screech

x2 -- why do you say "It is not a belt squeal"?

I'm very curious what the problem is because my K20 has recently developed a similar noise, usually around 1400 rpm. Doesn't always happen and I've been unable to duplicate it in my driveway. I tried soap on the belts -- adjusted the belts -- finally changed the belts. Still have the noise. I hope it's not the water pump, but I hope I find/fix it before changing coolant.

A thought on that fan clutch, if you think it's going bad. Inspect it closely for any hint of fluid leakage. Pay particular attention to the back of the unit, where the shaft joins the clutch. That seal might be leaking, and it's kinda hard to see, which makes it easy to miss. Doesn't take a lot of leakage to begin drying out inside.
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Old 09-24-2016, 02:00 PM   #5
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Re: diagnose screech

Try some belt dressing Stocker.
https://www.walmart.com/ip/Prestone-...ssing/16817510
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Old 09-24-2016, 02:04 PM   #6
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Re: diagnose screech

thankyou both for quick reply it sounds different more like metal to metal bearing screech and fan seems a little tight i have adjusted belt and no change im thinking bearing maybe alt. but i kind of think its fan clutch just wanted expert opinion ill change out belt to help diagnose n keep it for spare if you advise
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Old 09-24-2016, 02:08 PM   #7
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Re: diagnose screech

Well if its not the belt, then that'd leave you with water pump bearing or power steering pump, I think.
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Old 09-24-2016, 02:09 PM   #8
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Re: diagnose screech

only have one belt i installed good wrench engine with new water pump kept alt. and clutch fan and it did it before engine install thanks again you guys are amazing all of you
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Old 09-24-2016, 02:21 PM   #9
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Re: diagnose screech

Likely you have the wrong belt.
How deep does your belt sit in the pulley grooves?
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Old 09-24-2016, 02:22 PM   #10
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Re: diagnose screech

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low on cash would prefer to spend money on a new belt would that be an acceptable idea sir?
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Old 09-24-2016, 02:34 PM   #11
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Re: diagnose screech

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Likely you have the wrong belt.
How deep does your belt sit in the pulley grooves?
good idea my belt sits flush ps i have a motor neuron disease and with this touch screen phone itakes me forever to type response that isnt mispelled not complaining
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Old 09-24-2016, 02:35 PM   #12
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Re: diagnose screech

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low on cash would prefer to spend money on a new belt would that be an acceptable idea sir?
Yes!
If you need one!
How deep does the current one there sit in the groove?
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Old 09-24-2016, 02:41 PM   #13
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Re: diagnose screech

how freely should fan spin when engine is off and cold its kind of tight it does not free wheel. the shaft does look a little oil on it very minor
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Old 09-24-2016, 02:52 PM   #14
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Re: diagnose screech

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how freely should fan spin when engine is off and cold its kind of tight it does not free wheel. the shaft does look a little oil on it very minor
Hard to describe but I think of it as gooey like it's mired in molasses. It should not spin freely, and should stop as soon as you release it. No freewheeling. Yours sounds normal to me.
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Old 09-24-2016, 02:56 PM   #15
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Re: diagnose screech

current belt sits flush hope i describe this correctly the belt does not stick out above pulleys and the contour matches pulley it had wrong belt when i got it and i had the guy at auto parts store come out and look belt is two years old has mmm 10k miles on it I will buy belt and change and keep old one as i have spare carb. distrbutor hoses gaskets carb rebuildkit etc nothing wrong with extra fan belt
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Old 09-24-2016, 03:00 PM   #16
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Re: diagnose screech

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Thanks, but no. I tried it years ago and all it did was make a mess. I've had good luck verifying bad belts (or adjustment) by rubbing a bar of soap against the belt with the engine idling. Obviously anyone trying this needs to keep clothing & body parts safely away from moving belts / fans / pulleys!

Anyway I have already changed the belts which suggests there's no belt problem.
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Old 09-24-2016, 03:01 PM   #17
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Re: diagnose screech

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Originally Posted by 1969c10joe View Post
current belt sits flush hope i describe this correctly the belt does not stick out above pulleys and the contour matches pulley it had wrong belt when i got it and i had the guy at auto parts store come out and look belt is two years old has mmm 10k miles on it I will buy belt and change and keep old one as i have spare carb. distrbutor hoses gaskets carb rebuildkit etc nothing wrong with extra fan belt
Good description! One other thought -- do the pulleys line up? If not, that could cause a squeal (and shortened belt life).
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Old 09-24-2016, 03:11 PM   #18
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Re: diagnose screech

yes pulleys line up
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Old 09-24-2016, 03:16 PM   #19
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Re: diagnose screech

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good idea my belt sits flush ps i have a motor neuron disease and with this touch screen phone itakes me forever to type response that isnt mispelled not complaining
im sooruy meed break hsnds twitching too much now yhankyou im still teading rrdpondrd responsrd dam phine
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Old 09-24-2016, 03:30 PM   #20
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Re: diagnose screech

One last thing to check.
Unplug the voltage regulator and test again.
If no squeek then it's your altenator charging strongly that puts an extra load on the belt making it slip.
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Old 09-24-2016, 03:32 PM   #21
1969c10joe
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Re: diagnose screech

sometimrs i run out of patience i do know how to spell.Anything wring with removinh fan clutvh and starting engine . I only have to ruun it for a moment just thooughht of that
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Old 09-24-2016, 03:45 PM   #22
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Re: diagnose screech

You can run it without the fan for a a minute, sure (or less). But make sure the pulley is still bolted on. Don't just remove the fan and bolts! Anything's possible, but it seems like low odds it'd be the clutch making noise.
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Old 09-24-2016, 03:51 PM   #23
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Re: diagnose screech

Yeah, but it *could* be the water pump.... so removing the belt that turns the pump (which also turns the fan), then do a short test run, would help prove or disprove it.
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Old 09-24-2016, 04:20 PM   #24
1969c10joe
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Re: diagnose screech

Quote:
Originally Posted by geezer#99 View Post
One last thing to check.
Unplug the voltage regulator and test again.
If no squeek then it's your altenator charging strongly that puts an extra load on the belt making it slip.
i thought that unplugging reg would causr alt to run wide open?
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Old 09-24-2016, 04:39 PM   #25
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Re: diagnose screech

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Yeah, but it *could* be the water pump.... so removing the belt that turns the pump (which also turns the fan), then do a short test run, would help prove or disprove it.
if i remove belt and sound goes away then it could be belt alt water pump orfan clutch if its still there then its something rlse sound was there beforr new engine and nrw water pump i kept old alt and fan clutch
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