What is this vibration & Noise

[vpetersen]

My 97 4.0 has had new heads, all new egr, and new 02 sensors in the past 6 months. It runs great, and isn't throwing any codes, no cel. But, I do have this new problem and can't figure it out. When accelerating, or reving the engine in neutral, I start getting a vibration from about 2k rpms -3200 rpms. Then, around the time the vibration evens out I get a loud chatter. If I'm driving the vibration is felt though the whole vehicle, and then the chatter is there until it shifts gears. I first thought it was an issue from the tranny, but then I realized it does it when parked in neutral as well. Any ideas?

 

[claw32]

I would check the engine mounts first

 

[vpetersen]

ok, will do. Any other ideas? I know my description is kind of vague, is there anything I can do to locate the source of the problem?

 

[claw32]

I guess be watching the engine with the hood open and have someone else rev it in neutral and try to locate where the noise is coming from

 

[vpetersen]

ok so i got some time and a buddy to help out, with the trans in park we reved the engine and throughout the rpm range the engine is stable and there is no vibration. Around 2-3k rpm there is a chatter that sounds like its coming from the top of the engine. It sounds almost like a loose vibrating bearing of some sort. I guess it could be the valve train, but these heads are new/rebuilt from napa about 2k miles ago. I still have the vibration while accelerating but I think it is a separate issue, and I'd like to locate and try to solve the chattering issue first.