Name that sound
Thread Starter
Drifting
Joined: Feb 2001
Posts: 1,603
Likes: 0
From: San Francisco, CA
Engine sound diagnosis
My '76 L-82 has about 100,000 miles on it. Never any motor work done. Burns maybe a quart every 1500 miles. Runs pretty well actually. I have had what I thought might be valve tap or an exhaust leak tick that is not very noticable at idle but is under load. This seems to be getting worse . Now another sound has developed that is more troubling. At first I thought it was the ignition shield rattling but upon further inspection and getting under the car while it is running (on a Kwiklift) it is loudest when underneath the oil pan most noticeable on passanger side. It sounds like a metal on metal rattle or rubbing or knocking. Should I get a priest over here (the Vette is a Protestant I think) for last rights? :nopity
[Modified by R. Bruno, 8:22 PM 3/9/2003]
[Modified by R. Bruno, 8:22 PM 3/9/2003]
Race Director
Joined: Jun 2001
Posts: 16,483
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From: The Only Corvette in Gila Bend, Az.
St. Jude Donor '09
Re: Engine sound diagnosis (R. Bruno)
You could try changing your oil to a heavier weight, and see if it goes away while cold. The sound should return after it warms up again.....
if it does then it might be terminal... :(
Good luck, and keep us posted... :seeya
if it does then it might be terminal... :(
Good luck, and keep us posted... :seeya
Team Owner
Joined: May 2001
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From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
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St. Jude Donor '06-'10, '13
Re: Engine sound diagnosis (R. Bruno)
Funny thing is my truck has the same noise.
I have checked the valves 3 times now, searched for exhaust leaks and looked all over for loose parts.
I have no idea what it is, but we just took it on a 600 mile round trip and it ran 75 MPH + pulling a trailer and lived to take me to work every day.
I just wish I knew what that damn noise was ..... :confused:
I have checked the valves 3 times now, searched for exhaust leaks and looked all over for loose parts.
I have no idea what it is, but we just took it on a 600 mile round trip and it ran 75 MPH + pulling a trailer and lived to take me to work every day.
I just wish I knew what that damn noise was ..... :confused:
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 2
From: New Zealand
Re: Engine sound diagnosis (R. Bruno)
Have you checked the compression??? How about the engine mount??? Is there any noticeable change in performance??? Oil leaks around the pan???
Gee, I hate to sound optimistic, but bad noises don't necessarily mean bad things :)
Gee, I hate to sound optimistic, but bad noises don't necessarily mean bad things :)
Thread Starter
Drifting
Joined: Feb 2001
Posts: 1,603
Likes: 0
From: San Francisco, CA
Re: Engine sound diagnosis (standup)
I haven't cvhecked compression but there are plenty of oil leaks around the pan - 27 years of 'em. I just canged the valve cover gaskets for what I believe is the second time in its life. I haven't checked the engine mount but I got under the car with it running, up close and personal and it doesn't seem like it was that.
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Joined: Jun 2001
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From: The Only Corvette in Gila Bend, Az.
St. Jude Donor '09
Re: Engine sound diagnosis (R. Bruno)
Any guesses as to what it might be Dawg?
Thread Starter
Drifting
Joined: Feb 2001
Posts: 1,603
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From: San Francisco, CA
Re: Engine sound diagnosis (Desertdawg)
I am just learning about this stuff but I thought that the bearings seemed likely. The oil pressure (according to the gauge on the dash) has always been around 20 at idle but it doesn't move much when the rpm's come up. I read that this is an indicator of either a bad oil pump or bad bearings. It has been like this for years but maybe now it is coming to a head. I have been looking at crate motors and investigating the California smog issues in anticipation of this. So, assuming I am not going to rebuild, I thought just continue to drive the car until something happens - What will happen if the bearings are the problem? Thanks for the help. :cheers:
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Race Director
Joined: Jun 2001
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From: The Only Corvette in Gila Bend, Az.
St. Jude Donor '09
Re: Engine sound diagnosis (R. Bruno)
What will happen if the bearings are the problem? Thanks for the help. :cheers:
But if it happens at high RPM, you could very easily crack the block, and the rods will be toast. Then you will have to get a crate motor. Plus you will lose your numbers matching block.
If your not worried about numbers matching, and are really set on getting a crate motor, run it till it dies. If you want to rebuild your original motor, start thinking about tearing it down soon.