Vibration with A/C on.

[olopezm]

Hi guys,

it's been a long time.

My '97 GP has started showing this vibration only when the A/C is engaged; I had previously replaced the passenger side engine mount with one from autozone, however I'm not sure if it was a solid type mount or not, the clerk couldn't tell back then, I think it's been a year since then. Torque strut mounts (dog bones) are OK.

Is it possible that a failed mount is causing the problem or do you think the compressor might be going?

A/C system has proper charge.

Thanks in advance,

Oscar.

[Stealthee]

Sounds like the clutch on the compressor is failing. In the end, its easier to just replace the entire compressor, however, you would lose your AC charge.

[olopezm]

Thanks Stealthee,

I was thinking the same and I took it to the shop just to have the A/C system inspected. They found nothing wrong about it, and told me it would be a good idea to drain and replace the R134 just as a cautionary measure since the gas tends to get old, as he said.

That was the first time I ever hear that and don't know if it is actually possible but I just let them do it; I was nearby while they worked on it; they put some oil in and gas until properly charged.

Left the place and everything was OK until I went over a speed bump and started feeling the old rumbling as before. It becomes more noticeable at the moment the front of the car goes down and "leaves" the bump. Cycled the A/C on and off at different moments and sometimes I can feel the rumbling, some others don't.

What do you think? It still makes me think the mount might have gone bad; I've read numerous times about autozone's hydraulic mounts and how defective they can be.

Oscar.

[olopezm]

So today I finally got a clunk when switching between gears so I'll be replacing another mount. I wonder if it's actually causing the vibration when the A/C is on; I'm thinking the vibration more than being caused at the compressor should be more at the mount and with the higher power required when the A/C is running makes it "feel" like it's coming from the A/C.

Don't you think it would be possible? Anyway I'll be replacing the mount; is the mount on one side more prone to damage rather than the other?

Oscar.

[gmtech1]

If the mount does not fix it, take a good look at all the A/C lines and make sure they are secured where they need to be and not contacting anything they should not.