I'm a bit puzzled by the strange vibration and sound at 1500 RPM...it only happens at that RPM and when accelerating up a grade/ incline. Can anyone guess what this might be? The vehicle starts and runs great-just got back from a 1500 mile trip to South Carolina.
Open to advice and ideas about the vibration..... Thanks
1500 isnt too high, it will sit around 2500 rpm at 70/75 mph, right? at 1500 you are moving through gearing, have you noticed it on any specific gear cycle? if you are downshifting, then having to accelerate up a hill it could be driveline related, as in, when the gearing has dropped too low but you cant get the rpm back up to shift back up. check motor mounts, could be an rpm range that the engine doesnt like...???
i dont know of any issues with say prop shafts and u joints that would cause vibration ??
do you hear the sound under the car, left side, right side, front, rear, loud, does it increase in noise relative to speed?