Rod knock or something else?
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Joined: May 2019
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From: Michigan
Rod knock or something else?
Hi all - I had my car in to the dealer this week for an oil change and the tech said he though he detected rod knock. Can anyone tell from this short video if that might be the case? There's a loud and clear knock underneath the engine at idle, but it doesn't seem to worsen when I rev it to 3,000 rpm at the end.
Thanks!
Dan
Thanks!
Dan
Race Director
Joined: Oct 2004
Posts: 12,864
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Hi all - I had my car in to the dealer this week for an oil change and the tech said he though he detected rod knock. Can anyone tell from this short video if that might be the case? There's a loud and clear knock underneath the engine at idle, but it doesn't seem to worsen when I rev it to 3,000 rpm at the end.
Thanks!
Dan
Thanks!
Dan
Thread Starter
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Joined: May 2019
Posts: 72
Likes: 26
From: Michigan
Dan
Le Mans Master
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from what i can hear there is definitely something wrong. I would check valve trian to start with. Take off valve covers off and start from there. Me personally would not drive the car like that. Might be something simple.
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From: Michigan
Dan
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Le Mans Master
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From: Brighton MI
A rod knock is typically a "double knock" and more noticeable on free rev vs. under load. The noise I hear on the file you included is 1/2 engine speed, which means it is valve train related, not crankshaft related. Check the easy stuff first - rocker arms and pushrods. If no luck there, then you are probably pulling the heads to check the lifters and cam. Good luck. Please let us know what you find.
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Thread Starter
Advanced
Joined: May 2019
Posts: 72
Likes: 26
From: Michigan
A rod knock is typically a "double knock" and more noticeable on free rev vs. under load. The noise I hear on the file you included is 1/2 engine speed, which means it is valve train related, not crankshaft related. Check the easy stuff first - rocker arms and pushrods. If no luck there, then you are probably pulling the heads to check the lifters and cam. Good luck. Please let us know what you find.
Dan
Le Mans Master
Joined: Apr 2012
Posts: 7,814
Likes: 2,266
From: Brighton MI
If the noise is gone, I would not tear into the engine. It is possible you had a "stuck" lifter that has pumped back up. The closest tolerances in any vehicle are automatic trans valve bodies and lifters. The tiniest contaminant can cause an issue. It may have just flushed out the contaminants during your drive.