L_perm

Hi Folks,
I'm noticing through my feet--currently no carpet in the floor--a fairly small vibration that is cyclical--maybe once per second at idle--when the A/C compressor is on. I only notice it at idle, as other vibrations likely dwarf it when revs increase. Maybe it even goes away with higher revs.

Anyway, is this normal, or do I likely have a compressor bearing going bad? Or, something else?

Thanks,
Louis

Randy V

Could be normal, or it could be a broken compressor rear support bracket.

When I bought my GTS that bracket was broken and had to be replaced.

If it is cyclical, your compressor may be cycling on/off due to low refrigerant or a faulty sensor.

Mrmerlin

have the motor mounts been checked?
to see look at the oil pan it should be flush with the cross member.
look for the manifolds hitting if the mounts are collapsed, also check the trans mounts you should be able to fit your thumb tween the trans and the cross member

dr bob

^^^^ What Stan said. Collapsed mounts will transmit vibrations right to your feet and butt. Do check that compressor bracket. They are too often installed incorrectly if the compressor is serviced, and alo seem to break when a car is sagging on the springs and the compressor bumps something on the road.

Rob Edwards

On 90-95 cars, there are two A/C compressor brackets- 1 mounts on the block, the other mounts on the compressor. The two bolt together with two fine pitch M10 bolts. The 'block' bracket is weak and can crack just above one of the thru bolts that hold the compressor and its bracket.

Make sure the fore and aft compressor mounting bolts are tight:

L_perm

Thanks for the replies. My compressor bracket looks to be okay. I have some engine mounts (and tranny mounts) sitting in my garage now waiting for installation. Gotta go grab an engine support bar from Harbor Freight so I can get to the oil pan gasket while I'm down there--got a silicone gasket ready to go in too.

Thanks again,
Louis

DKWalser

Louis,

You might want to take the compressor off the car to inspect the bracket. Mine was cracked and was only being held together by compression from the through bolt. The crack was too fine to see with the naked eye -- before the through bolt was loosened. Then the crack became very visible!

L_perm

Good advice. Will do. Thanks DKW.