Grinding AC clutch engagement

Well I dont know where to start on this one. I was reading somewhere where some adjusted the air gap on the ac clutch. Could this be the problem. It only happens on the first startup of the day and after that everything is fine. Hot or cold weather the ac clutch makes the same noise. Any help would be appreciated.

Thanks

It could be some corrosion in there, it could be a weak relay that controls the A/C clutch (on my '96 the A/C clutch relay is part of the Constant Control Relay Module, aka CCRM), it could even be the compressor making the noise.
I had the relay inside the CCRM cause mine to cycle on and off quickly.

Another thing to check would be the electrical connections, starting with the one on top of the clutch unit......to rule out dirty contacts.

Well I dont know where to start on this one. I was reading somewhere where some adjusted the air gap on the ac clutch. Could this be the problem. It only happens on the first startup of the day and after that everything is fine. Hot or cold weather the ac clutch makes the same noise. Any help would be appreciated.

Thanks


Hi
I did make a post at some point stating that on my '96 I was able to narrow the clutch gap in a rather Mickey Mouse but effective way. I however was dealing with no clutch engagement during hot city type driving.

Perhaps you are dealing with a bit of slippage on that first start when the torque required to turn the compressor is perhaps higher than after it has run a bit....speculation.

Well I went out to try and do some trouble shooting on this one. Here is what I found. (BTW I have a 98) The AC engages in all modes but vent and off like it should (kinda surprised at that). The clutch disengages quite frequently (about every 2 minutes or so) and then reengages. The clutch stops when either of the high pressure switch or ac cycling switch is disconnected. I am wondering if my pressure is too high? I dont have any gauges to check it with. I dont believe the 98 has CCRM as Haynes doesnt show it. All connections are good. Any ideas??

Well I went out to try and do some trouble shooting on this one. Here is what I found. (BTW I have a 98) The AC engages in all modes but vent and off like it should (kinda surprised at that). The clutch disengages quite frequently (about every 2 minutes or so) and then reengages. The clutch stops when either of the high pressure switch or ac cycling switch is disconnected. I am wondering if my pressure is too high? I dont have any gauges to check it with. I dont believe the 98 has CCRM as Haynes doesnt show it. All connections are good. Any ideas??

Hi
the cycling of the clutch should be related to outside temperature. When it is colder, the cycling is more often so your 2 minutes may not be indicating a problem. Did you continue to have the "grinding" noise each time as the clutch engaged/disengaged?

Actually the grinding noise wasnt there and has been intermittent of late. The other day was cool so that would explain the cylcing of the AC. I think it actually might need a top up one of these days althogh it is still blowing cold air. I cant narrow down the grinding noise conditions as it doesnt seem to make any sense. Maybe I should have it evacuated and recharged.

Howdy,
Right off the top of my head, I can't remember how much of a cooling temperature drop of the air you should expect, but I'm guessing you should at least get 50 deg. F or lower coming out of the center vent . Possible to get all the way down to the high thirties, BUT I highly recommend an extremely well trained and experienced auto AC tech to get it that cold. I believe my 95 Windy that is that cold, has its factory charge or was done at the dealer if necessary when the dealer redid the head gaskets on it when it belonged to the inlaws. ANYWAY, if you look at the larger ac pipe that comes thru the firewall on pass. side and immediately to the dryer/accumulator (big thing), and also is where the charge port, low side, is located. This pipe should get cold and sweaty when running cold enough, and sometimes becomes frost covered. It is not unusual for the sweat to lead all the way to the compressor. But, that's not to say it is not overcharged. That would be very,very bad. But you never, ever want that pipe to frost up all the way to the compressor, because you may then have liquid rather than gas in the comp. which will kill it.

Now when the compressor starts for the very first time, that will be its easiest to start, than therafter it will be essentially the same other than the compressor getting hotter till it won't get hotter anymore. I've experienced what you are describing if it is slipping, but it wouldn't slip the first few times the clutch engaged but on later times and than wouldn't be able to turn the comp at all. HAVE you looked for something leaking or spraying on the ac clutch that might cause a slippage that might be making the noise you hear and then, with consequent engagements the contaminent wears, dries,etc. off, and no more noise. Grit, dirt debris? Oh, maybe the front bearing on the comp is complaing? Or the friction surface is nearly worn out? Good luck!!!:) :) :)

How did this turn out? What was the cause? I am having the exact same issue: http://www.automotiveforums.com/vbulletin/showthread.php?p=5793032#post5793032

88Exi, did your problem get fixed?