My engine has a high pitched harmonic vibration or resonance between 2000-2100 rpm, always has since I got it on the road a year ago. It happens whether driving or parked so unrelated to the rest of the drive train. I occurs both while reving up or coming back down through that rev range, throttle part open or closed. when parked with the hood up you can see and hear the air cleaner top buzz like crazy.
The engine runs smooth at all other RPMs, which leads me to think it's not an engine balance issue? It is a stock '88 5.0 short block/rotating assembly with a new stock replacement harmonic balancer. I am missing a couple teeth on the flywheel ring gear, not sure if that's enough to cause this? My only engine Accessories are the water pump and Alternator, I haven't tried removing the belt but imagine that's a good place to start?
Some searching seems to indicate this could be a resonance from the exhaust system, read someone's old post that they were told it had to do with the side pipes.
I try to not operate in that rev range as I'm afraid it's causing damage, however that makes it really annoying on the hwy in 5th as that range covers about 105-115 km/h that traffic often flows at.
Questions would be:
Anyone else experience this?
What is causing this?
Is there a fairly simple fix? Timing change?
Most important, am I hurting anything? I can live with it, especially at hwy speeds you can't really hear it.
Thanks in advance for your help!