thats what we need to know if it stops when you let off the throttle in gear. or if it continues. if its engine vibration it should do it in park in the driveway.
OK, took it for a test drive. It vibrates in each gear at the same RPM. The higher the RPM, the worse the vibration. In 3rd on the highway it starts at about 45 and gets worse from there. Let off on the gas and the vibration slows as the engine slows. Put it in neutral and it goes away completely. Rev the engine and it vibrates at the same RPM as when driving and gets worse the faster the engine speed. Took a peek under the hood when I got back, looks like the fan pulley is wobbly (double pulley for the AC and alternator). It's not loose. Perhaps the shaft on the water pump is bent. I'll have to take the belts off and see if it spins freely and if the shaft is damaged. The pump is not leaking. Hopefully this might be as simple as a new water pump.
