has it always done it, or just since you put the ES insert in?

Just a suggestion... Check your fan wires to make sure they aren't shorted anywhere or the fan motor isn't shorted out. If they were when the switch applied power to the wire, the current would surge causing a large drag on the alternator (power loss). Just a thought...

EDIT: You bastard for using A/C this time of year It's friggin 20 degrees here.

[Modified by Stew Pidasso, 9:44 AM 2/7/2003]

that what happens with the A/C and ES front motor insert, same exact thing my car does

Mine doesn't vibrate just when the A/C is on. It only vibrates when the A/C is on AND the fans switch on.

Geeezzz - its so c-c-cold up-p-p h-h-here I can't even get my AC to run.

Well, try this. Turn OFF your AC, run your engine (without driving) till the radiator fan runs. Does it vibrate this way?

If not, then I think what's vibrating isn't the fan, but the AC compressor. When the compressor clutch engages, it also turns on the fan. But the compressor takes more power to run than the fan, so that's what you feel (losing power).

Vibration could be the crank pulley starting to go bad & wobbling. The AC compressor is easily the biggest load on that pulley. Or maybe its normal but with the ES engine mount you just feel it more. That's the reason why they don't use stiff mounts as OE.

When the A/C is on.. the compressor is not immediately engaged ?? Does the compressor engage and disengage while the A/C is on ?

It started happening when I had the ES insert installed. I don't think it's the ES insert... because i only get vibrations when the radiator fans turn on. If they stay off, even when I have the A/C on, I don't get any vibrations. Weird.

When the A/C is on.. the compressor is not immediately engaged ?? Does the compressor engage and disengage while the A/C is on ?

Yes & no. When the AC it turned on, the compressor engages whenever it wants to. That's to keep the evaporator temperature where it should be. Whenever the compressor engages, it runs the fan too. So when you first turn on the AC, it needs to cool down so it engages right away. Once its cool it disengages. Then it cycles on & off as you drive. You feel its drag, cause the compressor sucks more power than just about any other accessory.

It started happening when I had the ES insert installed. I don't think it's the ES insert... because i only get vibrations when the radiator fans turn on. If they stay off, even when I have the A/C on, I don't get any vibrations. Weird.


It could be a wobbling pulley, so check that out. But more likely its been vibrating like that forever. The original soft engine mounts just absorbed the vibration so you didn't feel it. That's why they didn't put hard mounts in at the factory.

Watch the AC compressor with the engine idling. The clutch is external - it's all that extra stuff built into the pulley. When it engages you can see the clutch assembly spinning. When it disengages only the pulley spins. When it engages watch the belt - it should stay straight, not rattle like a rubber band.