Loud engine knock, but no codes. Please help.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
It doesn't cost anything to pull the valve covers off and check the valve train. Can be accomplished with simple hand tools. You have to know someone that can help you.
Hard to tell from the Vid. Give that a look see and go from there.. If you don't see any thing wrong up top,,,,, You need engine work/replacement!
Bill
Hard to tell from the Vid. Give that a look see and go from there.. If you don't see any thing wrong up top,,,,, You need engine work/replacement!
Bill
Drifting
Joined: Mar 2018
Posts: 1,365
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From: New Jersey
It's hard to tell from the video if it's a rod knock with the engine idling. Do you have lower than normal oil pressure? With a rod knock, if you race the engine up to about 2,000 RPM or so it will get a lot louder and the sound can go away or become quieter as the engine loses RPM. It will also get louder as the engine warms up. You can also drain the oil and if you have a lot of silvery stuff in there you know you probably spun a bearing.
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Joined: Mar 2004
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From: Fort Wayne IN
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Pop the valve covers and find the rocker slapping around. Then see why it was slapping around. Could be any number of things, from something as simple as a bolt loosening, broken valve spring, or more involved such as a collapsed lifter (head pull job there), spun lifter (which would wipe out the lifter and camshaft), etc.
I doubt that's rod knock. That's all valvetrain IMO. Heard it before in a variety of ways and it all sounded like that when it was the valvetrain. There's a lot of moving parts that causes a conglomeration of sounds, but none of them are as deep and "thuddy" as a main/rod bearing.
I doubt that's rod knock. That's all valvetrain IMO. Heard it before in a variety of ways and it all sounded like that when it was the valvetrain. There's a lot of moving parts that causes a conglomeration of sounds, but none of them are as deep and "thuddy" as a main/rod bearing.
Advanced
Joined: Jun 2018
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Have you figured it out yet? I’m very interested in seeing what that noise is. I’m thinking it’s a rocker arm that came loose because the sound seems very high up and not a deep knocking pitch, though the theory with the water getting into the motor and hydro locking a piston is very plausible.
