Engine Gurus---what could cause this squeak?
Thread Starter
Instructor
Joined: Oct 1999
Posts: 139
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From: So. Miami
Engine Gurus---what could cause this squeak?
Been away for a while but back now....Of course the same problems with the car waited for me to get back!!!!!
This is driving me nucking futz.
ONLY when the engine is hot and ONLY at idle, there is a high pitched squeak coming from under the timing chain cover. I'm sure this is where it originates because I checked it with a mechanics stethascope, and undid all the belts after a long drive when it was hot to rule out pulley/belt noise.
I'm idleing at 550-650 RPM in drive. If I raise the RPM just a bit----to say 800-850RPM, the squeak goes away. Come back to idle and the noise comes back.
The timing chain/gearset have less than 1000 miles. I am running a Comp Cams regular Hyd. cam-268H I think.
HELP!!!!!
I sure would appreciate any ideas :cheers:
Thanks,
Gary
This is driving me nucking futz.
ONLY when the engine is hot and ONLY at idle, there is a high pitched squeak coming from under the timing chain cover. I'm sure this is where it originates because I checked it with a mechanics stethascope, and undid all the belts after a long drive when it was hot to rule out pulley/belt noise.
I'm idleing at 550-650 RPM in drive. If I raise the RPM just a bit----to say 800-850RPM, the squeak goes away. Come back to idle and the noise comes back.
The timing chain/gearset have less than 1000 miles. I am running a Comp Cams regular Hyd. cam-268H I think.
HELP!!!!!
I sure would appreciate any ideas :cheers:
Thanks,
Gary
Race Director
Joined: Sep 2002
Posts: 10,362
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From: San Diego - Deep Within The State of CONFUSION!
Re: Engine Gurus---what could cause this squeak? (7tea1)
Is the PCV system vented? A common prob with folks that install ZZ4 engines is they leave that little red plug in the right side valve cover and of course, put the PCV valve in the left one.
At idle there is enough vacuum to suck air thru the rear main seal. :mad :rolleyes: Trust me. It makes a horrendous noise!!
All it takes is to throw the red plug in the trash and install a vent filter so that the PCV can properly VENT the CRANKCASE.
So the 100 dollar question is this: does this situation sound familiar? I cannot tell from your signature if this is possible ... was this noise always a prob? Let us know.
Paul in San Diego :flag
At idle there is enough vacuum to suck air thru the rear main seal. :mad :rolleyes: Trust me. It makes a horrendous noise!!
All it takes is to throw the red plug in the trash and install a vent filter so that the PCV can properly VENT the CRANKCASE.
So the 100 dollar question is this: does this situation sound familiar? I cannot tell from your signature if this is possible ... was this noise always a prob? Let us know.
Paul in San Diego :flag
Drifting
Joined: Jul 2002
Posts: 1,944
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From: The only Corvettes in Highett Victoria
Re: Engine Gurus---what could cause this squeak? (7tea1)
Easy problem to solve--just pop the hood and look for a mouse. You're sure to find one there. If not, look for a rat! :lol: :jester :D
Regards from Down Under
aussiejohn :cheers:
Regards from Down Under
aussiejohn :cheers:
Drifting
Joined: Jul 2002
Posts: 1,855
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From: Cocoa Beach FL
Re: Engine Gurus---what could cause this squeak? (SanDiegoPaul)
This sounds all to familiar to what I was experiencing a while back. SDP nailed it for me...replace little pink plug with breather and the squeal went away! Hopefully your problem is as simple.
Would the venting problem still be an issue if the valve covers only had one hole on each? DOes the crankcase need more ventilation? Just curious.
:thumbs:
Would the venting problem still be an issue if the valve covers only had one hole on each? DOes the crankcase need more ventilation? Just curious.
:thumbs:
Thread Starter
Instructor
Joined: Oct 1999
Posts: 139
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From: So. Miami
Re: Engine Gurus---what could cause this squeak? (Mystery Machine)
Thanks folks for the help but, it is a squeak---not a squeal.
It is the factory base 350.
I'm sure it is not a vac/suction issue.
Like I mentioned, ONLY at idle and ONLY hot, from under the timing chain cover.
Keep 'em coming!
Thanks
It is the factory base 350.
I'm sure it is not a vac/suction issue.
Like I mentioned, ONLY at idle and ONLY hot, from under the timing chain cover.
Keep 'em coming!
Thanks
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Re: Engine Gurus---what could cause this squeak? (7tea1)
It is the factory base 350.
I'm sure it is not a vac/suction issue.
Like I mentioned, ONLY at idle and ONLY hot, from under the timing chain cover.
OK then, if it is the factory engine, then how many miles on it? What does the oil look like? Next, pull all the belts off the motor and fire it up. If it is an accessory making the noise then it will go away.
Put the belts on one by one until you hear the noise. It may be the water pump.
I'm sure it is not a vac/suction issue.
Like I mentioned, ONLY at idle and ONLY hot, from under the timing chain cover.
OK then, if it is the factory engine, then how many miles on it? What does the oil look like? Next, pull all the belts off the motor and fire it up. If it is an accessory making the noise then it will go away.
Put the belts on one by one until you hear the noise. It may be the water pump.
Drifting
Joined: Jan 2002
Posts: 1,645
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From: Schaumburg IL
Re: Engine Gurus---what could cause this squeak? (SanDiegoPaul)
Hey buddy, if the belts and the water pump are not the fault and it only does it when really warm your area of where it comes from is probably right. If the crank or cam gear is misaliged from wear and when it heats up fully, you may be rubbing on the block metal to metal just enough to make the howl. I have run into this and eventualy it weakens enough that - crash :banghead: and break. Check it out. Hope it is the belts or WP.
Thread Starter
Instructor
Joined: Oct 1999
Posts: 139
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From: So. Miami
Re: Engine Gurus---what could cause this squeak? (bigvette1)
bigvette1,
I'm gonna have to pull the timing cover to check this out. Like I mentioned in my 1st post, I have ruled out accessories, WP, and belts.
I was also wondering if the cam could be "walking" out a bit. I DO NOT have a cam button on it. Just a thought.
I'm gonna have to pull the timing cover to check this out. Like I mentioned in my 1st post, I have ruled out accessories, WP, and belts.
I was also wondering if the cam could be "walking" out a bit. I DO NOT have a cam button on it. Just a thought.
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From: Ft Walton Bch FL
Re: Engine Gurus---what could cause this squeak? (bigvette1)
Did you by chance put a thrust button on the front of the cam? Or a double chain that might be barely touching at idle? I think that if so, you could pull the distributor and pry forward some on the drive gear to buy a little clearance, then try running it again. Worse case, you should pull the cover off and look for a rub spot. Good luck.
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From: Dove Mountain Arizona
Re: Engine Gurus---what could cause this squeak? (7tea1)
Kinda got the same problem with mine. It's all new. I do have aluminum full roller rockers and tall valve covers. When I pulled the covers off the old engine in prep for removal I noticed that probably two of the rockers seemed to be slightly rubbing on the inside of the valve cover on the pushrod side. I was gonna 'clearance' the covers but forgot. Got pretty much the same noise I had with the old engine now. Gonna stick a stethascope on it tonight to verify. Just a thought for ya....... :cheers:
