Lower Engine rattle noise at operation temperature.
Thread Starter
Heel & Toe
Joined: Mar 2005
Posts: 18
Likes: 0
Lower Engine rattle noise at operation temperature.
Hi Everyone,
I am the original owner of a 92 LT1 with 180,000 miles on it and it starts and runs fine but when it warms up I get an engine noise coming from the lower part of the motor on both sides. It doesn't sound like it is coming from the top end and it steadily gets louder as the car warms up and then the engine starts to idle rough. It get a code 32 but that doesn't sound like it would cause this. I am thinking the rod bearings are starting to go. Any ideas?
Motorcycle guy.
I am the original owner of a 92 LT1 with 180,000 miles on it and it starts and runs fine but when it warms up I get an engine noise coming from the lower part of the motor on both sides. It doesn't sound like it is coming from the top end and it steadily gets louder as the car warms up and then the engine starts to idle rough. It get a code 32 but that doesn't sound like it would cause this. I am thinking the rod bearings are starting to go. Any ideas?
Motorcycle guy.
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
I think piston slap is more of a cold condition that goes away when the engine reaches temp.
Of course it could be bearings. Also timing chain wear, balancer, exhaust leak, timing (opti, rotor, contacts) If it's a manual trans, could be slop developing in the DMF. If it's bearings I would think the sound would get louder with rpm's. Pulling the pan and taking a look might be a good idea though. If a bearing hasn't spun and there's no crank damage, I understand that bearings can be changed without pullling the motor or heads. At 180K it might not be a bad idea anyway.
Of course it could be bearings. Also timing chain wear, balancer, exhaust leak, timing (opti, rotor, contacts) If it's a manual trans, could be slop developing in the DMF. If it's bearings I would think the sound would get louder with rpm's. Pulling the pan and taking a look might be a good idea though. If a bearing hasn't spun and there's no crank damage, I understand that bearings can be changed without pullling the motor or heads. At 180K it might not be a bad idea anyway.
Thread Starter
Heel & Toe
Joined: Mar 2005
Posts: 18
Likes: 0
It sounds like a diesel rattle and the oil pressure is fine most of the time but it does fluctuate wildly when at idle periodically but goes away when I press on the gas. I also notice a slight exhaust leak from the manifold also but no sound at that location.
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