'99 Civic loud squealing

[maxzoran]

Hi there! Thanks in advance for the assistance! I need help diagnosing a problem on my car so I can fix it. Upon start up with the a/c on, the car runs fine. About a minute after start up, an extremely loud squealing noise develops. When this happens the idle RPM drop really low almost to the point to where the car wants to stall. When I turn off the a/c, the squealing stops and the RPM jump back up to normal. It doesn't appear to be affected one way another by the fan, just the a/c. So obviously this is an a/c problem...what could it possibly be? Can I drive the car without a/c until I get it fixed without doing a lot of harm? thanks! Max

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[RonJ@HT]

Check whether the A/C compressor belt is loose or contaminated with oil.

[Vindicator9000]

Originally Posted by maxzoran

Hi there! Thanks in advance for the assistance!

I need help diagnosing a problem on my car so I can fix it. Upon start up with the a/c on, the car runs fine. About a minute after start up, an extremely loud squealing noise develops. When this happens the idle RPM drop really low almost to the point to where the car wants to stall. When I turn off the a/c, the squealing stops and the RPM jump back up to normal. It doesn't appear to be affected one way another by the fan, just the a/c. So obviously this is an a/c problem...what could it possibly be? Can I drive the car without a/c until I get it fixed without doing a lot of harm?

thanks!

Max

Is it a belt squeal, or a metal on metal squeal?

If it's metal on metal, it's either AC clutch or compressor going out. It's much more likely the clutch, depending on mileage of the car, although if the compressor's not turning freely when the AC clutch is engaged, it could cause the same symptoms.

If it's AC clutch, it's a fairly cheap and easy fix:

The clutch is a circular thingy that rides on the far outside of the AC pulley. It's held on with a few bolts, and moves inward to engage the compressor when you turn on the AC. When the clutch runs out of friction surface, you start to get a horrible metal on metal squeal when you turn the AC on, start the car with AC on, or sometimes even accelerate hard with the AC on... or, sometimes, it'll just come and go on its own with the AC on, as I found out.

The super cheap and easy way to fix it is to get an AC clutch disc from the junkyard. I paid $10 for mine, and it's lasted 1 year so far. Still works good, even though it didn't really look so great. You simply pull 3 bolts and swap the outside disc. Fair warning, it is a bit difficult to pull the clutch disc in a junkyard because the pulley will keep wanting to spin. I jammed a screwdriver in it and was able to get the bolts off and pull the clutch.

If you decide to go with brand new parts, Honda does not sell the disc by itself, but instead sell a kit that replaced the clutch, AC pulley, and a few other things. It's a little bit over $100 last time I checked.


If it's belt squeal, just clean, retension, or replace the belt.

[maxzoran]

I haven't checked the tension yet, but I will get on that ASAP. How can I tell the difference between a belt squeal and metal on metal. It's VERY loud and VERY high pitched.

[RonJ@HT]

If the A/C belt seems snug and clean, then it's likely a bad compressor clutch mechanism or bearing.