I notice my engine vibrates right around 1700 rpm, anything less or more is perfectly smooth. It does it whether the car is siting still or going down the road. It doesn't jump or anything when I put it in gear, so I don't think it's the motor mounts. Could this be the harmonic balancer?


('87 350 TPI)

It's possible. Could also be motor mounts. Could be the A/F mixture (I wouldn't think so since it happens both still and driving). Could be really anything that is part of the rotating assembly of the engine from the harmonic balancer to the torque converter.

The main thing that kills harmonic balancers is when they are installed using a hammer. There is a special tool for installing/removing them.

Hmm, well my torque converter doesn't lock up. I'm going to replace the TCC solenoid soon, so I'll see if it even works at all after that.

I would also assume that if the veins in the converter decided to move to another part in the converter that would throw off the balance. Kinda like if someone moved the wheel weights around randomly.