I have a 2000 3.0. It has a loud rattle which appears to be coming from the air plenum on top. When it first started it would only do it when cold. Now it does it even when hot at idle. Turn on the AC and load the engine and it gets worse. Took off the belts to make sure it wasn't something they were driving causing it. Didn't make a difference other than couldn't load the engnine with the accessories. I can lay my hand on the plenum and throttle body and can feel it. When raising the rpm it seemed to go away but with hand on plenum you can feel the change in frequency but it does get quieter. What can cause this? Is it something that needs to be fixed soon? I have some trips to make this week (300 mile roundtrip).

 

Similar but not the plenum: https://dodgeforum.com/forum/dodge-c...ine-noise.html

 

Also when I put it in gear the noise quits. I took it by a shop today and they couldn't tell for sure but it sounds like it is on top. I am to take it back when I get back from my trip so they can put it on a lift and get under it and listen and probe around.

 

Finally got it into the shop last night. He just called and said it was the flywheel/flexplate cracked. He said they see a lot of these on the 3.0 engine.