2900 Rpm vibation

[Aaron S]

I can't say I noticed when it started, but I have noticed a vibration around 2900 rpm and up. The truck runs fine and is smooth otherwise. The vibration is there if the engine is under a load or not. It has done it with two different transmissions and flex plates.

I haven't run it up to that rpm in park though to see if there is any difference. I should probably try that and then pull the belt and try again. The crankshaft damper/ balancer looks ok.

Any ideas for things to try would be appreciated.

Thanks

 

[Gary]

Do you feel a power loss? Does it do it in park and neutral?