Sea Bass

About a year ago, I noticed my car (2002 Civic EX with 257k) at idle had a very very quiet, low-pitched whine. It was rhythmic, and made me think one of the belts was a little squeaky, most likely connected to my power steering pump due to a separate issue (long story). So I ignored it.

Then late in the summer, my AC started intermittently working, but again I ignored it because summer was almost over and I figured I'd get a freon recharge next spring and that'd probably fix it.

Now that summer is here again, when I start my car and turn on the AC, something under the hood will SCREAM at me. When I open the hood, it's literally ear-piercing. It sounds like a belt wining but I initially couldn't locate the exact location of the sound. Turning off the AC fixed made the whining stop. Again, during hot days, my AC would blow ice cold for a while (and whine) and then it would quit just like last year. It seemed to quit more on hot days then on mild days.

I watched this super informative video on youtube where a guy showed how the intermittent working of the AC could be due to the magnets not engaging in the pulley due to excess wear, and removing a washer can fix the problem:


HOWEVER, in the video, he shows how hitting the pulley with a screwdriver can engage the it and get the AC working again. This is not my problem. For my car, I noticed when the AC quits, the pulley does stop spinning, but hitting hard with screwdriver or hammer doesn't get it to work. When it does work (for example, when I start it after it sits for a while) the pulley will start spinning but it squeaks.

So here's my theory: the ball bearings or something is worn out on the pulley. I think the compressor is still good and there's still freon in it, but I need to replace whatever is causing the squeaking noise.

What's your best guess on what parts I might need off eBay? How big of a project will this be? I don't want to de-pressurize the system or replace the entire compressor, so any advice is much appreciated!

ezone

Test, don't guess.
When it acts up and completely stops working you need to figure out:

Does the clutch relay click?
Does the relay supply power thru its contacts; Is the clutch receiving 12v to engage? Does it engage at that time?
Ohm check the field coil, is it somewhere around 4 ohms?

Remember, you have to figure all this out WHILE it's broken. Once it starts working again you won't gain anything.

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How large is the air gap between the clutch plate and pulley? Does it look like it's 1mm or more? Have you checked and removed any shims yet? (target is 0.5mm gap)
When you beat on (something), you were supposed to use a tool to PUSH the outer clutch plate toward the pulley, and if it engages with that assistance and runs then indicates the gap is too large or the field is too weak. If it engaged, then that means the relay and wiring all worked at that moment.

The loud screech is probably just a loose belt. (EDIT: or ruined by oil contamination)
Remove the drive belt and spin the compressor pulley by hand. Does it sound rough or loud? Does the pulley have a lot of play in it?
When you put it back together it needs to be tighter than it was. Or replace the belt if it's worn/cracking, and consider the timing belt might be just as bad.

Sea Bass

Damn. Okay, so I guess there's some things I haven't checked. And it sounds like all these issues can't be eliminated with one fix. BUT, I can tell you that I tried multiple different ways to push on the outer clutch plate to get it to engage and it wouldn't. When the AC is working, the squeak comes from the outer clutch plate, I'm sure of that much. Once the AC stops working, there is no squeal or squeak, and when I turn the AC on/off it's as if nothing is engaging or clicking. It really seems like the AC working for a little bit, then freezes up due to grinding or something.

I don't think the timing belt is bad. I changed it at 217k. I don't think there's an oil contamination problem.

ezone

Ok then, testing for power to the clutch coil, and ohm checking the clutch coil would be next.

But wait, let me ask you this: Do both radiator fans keep running when the compressor quits engaging? Push the AC button a few times, the fans still turn off and on every time you push the AC button?


I thought you mentioned something about the power steering leaking on a belt.

Sea Bass

Yes, both fans keep running when the compressor quits engaging. That was definitely something I initially checked for.

I have a power steering issue, but it's not due to fluid leaking. Maybe I shouldn't have brought it up since it has nothing to do with my AC. I only mentioned it because that is what I initially thought caused the squeaking, but one has nothing to do with the other. Long story short, I think the pump is going bad, but no fluid is leaking at all.

Thanks for your help! I welcome any more input on this issue

ezone

Ok so that tells me the PCM (which controls the compressor clutch relay and fan relays) should be trying to operate the compressor.

So I'd probably continue with testing for power to the clutch coil, and ohm check the clutch coil