Vibration with AC compressor operating

[xenon]

'99 LC has a noticeable vibration when the AC compressor is on. It can be felt through the steering wheel at idle and can be heard as well.
I'm not particularly worried about this, as it has been going on for the last 18 months and the AC works fine.
This started (I think) around the time I had the timing belt and water pump replaced. There may be no connection whatever; then again there might be.
Any thoughts on what might cause this?

 

[spressomon]

'99 LC has a noticeable vibration when the AC compressor is on. It can be felt through the steering wheel at idle and can be heard as well.
I'm not particularly worried about this, as it has been going on for the last 18 months and the AC works fine.
This started (I think) around the time I had the timing belt and water pump replaced. There may be no connection whatever; then again there might be.
Any thoughts on what might cause this?

Have you checked the three bolts that hold the compressor in place? FYI: Two of these need to be removed when replacing the t-belt.

 

[richg]

The ECU raises the engine RPM when the compressor kicks on. This increase in RPM can result in increased perceived vibration. I know in my 98 I can tell when the compressor kicks on and turns off when sitting still at idle, but its something that no one else in the truck notices.

rich

 

[matt60/80]

I've had a similar thing happen with my 80 and the compressor crapped out; but I do believe the system developed a leak under the loving care of a PO (currently being checked out). Anyway don't sweat it, I notice the same thing you're describing with my parents Echo, Tacoma, 4Runner and a friend's Rav4.

 

[NMuzj100]

Have you checked the three bolts that hold the compressor in place? FYI: Two of these need to be removed when replacing the t-belt.

This sounds like a good plan.