A/C Compressor About to Grenade

On my daughter's ALH wagon, it runs and idles great.
However, turning on the a.c. while idling causes a noticeable strain on the engine, more so than normal I think. Is a bearing about to seize? Is the compressor failing? Is there any way to test a compressor? (Yes it still cools just fine.) Should I just bite the bullet and replace it? After all, getting 340k on the original compressor in Richmond, VA doesn't seem too disappointing to me.

It's more probably the clutch and not the compressor. You can just changed the clutch and bearing assy separately from the compressor......I have done 4 so far, it's not hard, first time about 2 hours, now I've gotten it down to about 45 minutes.

Thanks for the quick responses.

I will check the alternator clutch, although I doubt that's the problem. I change it at every timing belt service so this one is 40,000 miles old and I bought it from idparts. Also, the engine laboring happens only when the ac is switched on and stops instantly when the ac is switched off.

If the clutch pulley bearing was bad, it would be making noise while unengaged (freewheeling), right? My understanding is that once the clutch pulls in and locks the pulley to the shaft, that bearing is not functioning as a bearing. The fact that the clutch is working (ac works) and the laboring happens when the clutch is engaged is the reason I suspect a bearing within the compressor itself. Am I missing something?

On mine it stalled the engine, stopped to pick up a pizza , came out to start the car , sounded like the battery was dead. Tried popping the clutch with several people pushing no dice........finally cut the acc belt and the car started right up..... Drove home that way, changed the clutch out the next day as I had ordered one a few days earlier. Just .02

Nope! The AC pulley bearing rotates continuously when the engine is running, engaged or not. If that pulley is rotating, it's bearing is also rotating.

I do not want to say the issue is the AC compressor bearing, as you didn't say there is grinding, knocking, pecking, etc., just pulling the engine down. Does the RPM rebound at idle when the AC is turned ON? Maybe attaching a set of AC Manifold gauges would be helpful with respect to knowing what's going on with pressures.

Hmm... I've never had Steve's situation, where the clutch locked up the engine.

Most commonly, if the clutch engages, and there are no bearing noises, I have to blame the pump, especially if the engine lugs when the ac pump clutch is engaged.

I agree, check pressures for the AC, but I'm more likely to think it's a bad pump and the shaft would turn hard or might feel like it has rough bearings internal to the ac pump.

I don't know anyone else who changes the ac clutch with the timing belt. I think that is a great way to take a good part and exchange it for CRAP. I've seen OEM clutches last hugh mileage. It certainly does not need changed every 100k.

Franko6, I change the alternator pulley with the timing belt. I have never changed the a.c. clutch. It's original along with the compressor. I am going to put a stethoscope on the compressor when it's running and report back.

I see now... It's easy enough to tell when the alternator hubs go bad, and for most of them, it gets changed right in the engine bay. I just don't assume they are going to go bad.

I will be looking for an answer.

Frank you are correct, the clutch itself didn't lock up, the bearing that's part of the clutch assy greanaded and locked the clutch to the pulley. When I shut the engine off it was too much for the starter to start the car and engage the compressor at once when I came back out with the pizza.

With 340k on an A/c pump I would not even think about trying to rehab any clutch or bearing. The failure of the pump or seal is probably not far behind. I have had good service with the rebuilds offered on Ebay and I use the a/c quite a bit. Sometimes the rebuilds are so cheap they are about the same price as the clutch assembly. One time I bought a rebuild and just pulled the clutch off to use on another car.

tgray said:

With 340k on an A/c pump I would not even think about trying to rehab any clutch or bearing. The failure of the pump or seal is probably not far behind....

Click to expand...

My thoughts exactly. And the way I approach repairs on this car is different now that I've handed it down to her. If I was still driving it, I might take more of a wait and see attitude. But since I only have it for a week or two at a time maybe twice a year, I'm inclined to do a big fix that assures me it won't give her trouble five hours from home.

I have almost 400,xxx miles on my car, the ac pump is original, I use it all the time.
I am currently on my third ac clutch assy. First one was an open circuit, not causing ac to engage, the second one literally burnt up taking out the bearing an preventing me from starting my car, currently running third one.

Who's to say that the rebuilds are gonna be any better, I moths be newer but not necessarily better..... Just my .02.
If the pump is good run with it......don't change it because of mileage .

An eBay Clutch Assembly (face, pulley with bearing and coil) can be shipped to your door for less than $50.00. With the correct tools, you can change it in less than an hour. The last one I purchased was either German Made or a super darn good copy.

Try turning the front part of the A/C clutch by hand with the engine off. It should turn smoothly, with some effort. Compare the feel to one of your other vehicles for comparison. If it's quiet when running, it could be the idle up system is not working. The computer kicks up the idle speed as soon as the compressor clutch engages to compensate for the extra load on the engine. If this fails, the engine idle speed will drop even though the compressor is good.

I went ahead and ordered a new clutch/pulley and plan to change that out and see what happens. If it fixes the problem, that's great. If it does not and I determine the compressor itself is the problem, I'll keep this clutch/pulley as a spare for my other ALH wagon.

UPDATE (and question)

Got the old clutch/pulley off and the new one on. However should the pulley spin completely free when the clutch is not engaged? Mine does not. When the nut is torqued to 11 ft lbs turning the pulley causes the clutch to turn a bit (slight rubbing). There was (I believe) one spacer washer on the old one which I reused. Thinking of taking it off and adding one of the two new ones that came with the new one. How much of a gap is too much? Thoughts?

Done. Pulled it back off, replaced the one old used spacer with 2 new ones, put it all back together and it runs a like new. Thanks everyone.

Very nice!

Instead of trying to twist myself in a pretzel or unbolt the compressor and then try to hold it steady to do the work, I removed everything in front of the pulley (wheel well splash guard, intercooler and its bracket, etc.) leaving loads of room to work. Took a little longer but with a whole lot less cursing.