I got a weird thunk hallow sound when I rev my engine to 3k rpm. It just has it once. I let the gas down, and rev it back to 3k and that thunk hallow noise is there again. This only happens when I have it on park, and revving the engine. It's not a continuous thunk noise. I can go to 5k and it won't be there.

I took it to the highway and rev it up to 4k rpms and no thunk. Only on park. Sounds like its inside the engine. Any ideas? Oil is full, just changed 2 weeks ago, and so is tranny fluid. Just changed 4 days ago. Car drives good. It's a honda accord 2000 ex with 170k miles.

 

Could it be maybe a leak at the exhaust manifold? Maybe you got a hole in your downpipe. There was a thunk in my engine when that happened.

 

How did your car run? Did it run good like mine did?