I remember many years ago I had a 70 ss chevelle with a 396and I was pushing it pretty hard when I heard a loud squealing noise "as you did". When I came to a stop ""idle" the oil light was blinking and had a deep knock, I goosed the motor and the oil light went off and knocked increased with RPM. I had it towed home pulled the motor and tore it down and # 3 bearing had spun out and destroyed the crank and contaminated the motor with bearing debri...
Sorry to say but sounds like you have no choice but to pull the motor and do a tear, rebuild or replace motor, goodluck!

good tip, I will start with that, also have a real mechanic coming down to listen to her Friday, sux cause my buddy had the top end redone last year for decent coin $$

we didn't even hit 1500 rpm on this one...

Let us know what you find in the oil and filter. Be sure to save the oil to show your mechanic.


Check out this link sir. http://www.stockcarracing.com/techar...nspection.html

okay so we pulled oil filter, cut open (with a hacksaw, as we had no choice) no metal shavings besides what we created, however is was very milky, but the oil on the dipstick still looks decent. I'm guessing water intrusion, maybe intake manifold gasket? could th noise be from compromised oil maybe?

Thats why I suggested the intake gasket sir. I'm glad you didnt find any "flakes" in the filter, as that indicates that whatever the problem is...you caught it early. It almost seems to me from your story, that the motor never ran great from the time you got it back from the mechanic. If he re-did the heads..he obviously had the intake off (gaskets), and if it was sucking in even a super slight amount of water, that may have been why it was running rough on that/those cylinders. Off course, I'm just guessing at this...but I'd pull it if it were mine. I'd definately be having a talk with the guy who put it back together..he may work something out with you. You still have a whole season ahead of you. Do it right sir.

Yes your suggestion is where I got that from, lol... So next is pull intake I guess.... It's a friends boat, and he is so disgusted and ready to quit, but I'm trying to save his season.
Thanks for all the input tinman, and everyone!

Sir...the "loud tap or quiet knock" is more what I'm worried about. What is/was your oil pressure at ? Please dont guess...its important. Make sure the tap or knock isnt an exhaust manifold leak. In my opinion...as it isnt that hard to pull the motor...I'd take it out, flip it over, and check all the bearings. With 2 guys, you could actually have an answer in a few hours....and PEACE OF MIND. Dont let your buddy get discouraged. This is how you learn, and he'll prolly be happy knowing he did the work himself. It's a nice feeling running down the lake/river knowing that YOU YOURSELF made the motor right. Good luck sir...there's alotta smart guys on this site here for ya.

Hey just a little info here on cutting open oil filter. DON'T USE A HACKSAW OR CUTOFF SAW TO OPEN IT! Debris in the filter media is deposited on the outside pleats and any cutting with hacksaw or cutoff saw will deposit all kinds of good metal to look at in the pleats!
You will scare yourself to death easier if you use the saw open method and it will be very hard to differentiate between what metals what.
Yes they actually make filter cutting tools, see Summit or others, not to expensive, but a carefully punched hole followed by good sharp tin snips will do the trick up near the top of the filter base. Do this cutting base up and then pay attention also to whats in the bottom of the filter can. A good magnet is helpful for iron and steel particles, but not for bearing material.

Knocks are not good on fire-ups but sometimes they can just be from lifters and such. If they get louder under a load then that's not good and generally indicates an internal engine issue like bearing, piston pin, piston, etc.

Hope your engine is OK and this is just spring time first use flutter.

Best Regards,
Ray @ Raylar

The repetitive squeaking noise combined with the rough running, puff through the intake, and a water intrusion issue would make me think you have a stuck/sticking valve. Do a compression check.

If you wait a few minutes and start the engine again, does it run O.K. for a short while?