Help diagnose this engine noise at 5000 RPM, video
Odd thing happened today...
I dont typically rev my 4.0L this high but i was on the highway passing and i noticed when the engine revved to around 5000 RPM, there was this sound, i presume coming from the motor. its a very fast "Sheesh sheeesh sheesh" noise until the RPMs drop.
you can hear it in this video as the RPMs jump up, then a very short "sheesh" after they are coming down quick, i can reproduce it every time.
truck is running solid, i cant recall ever hearing this before, although i typically dont rev above 4000-4500 anyways.
is this valve float? or something i should get checked out under warranty?
2007 4.0L xlt 4x4 55,000mi
the tank had half regular and half 93 octane in it.