2003 V6 intermittent a/c problem

[LeedsAL]

I have a 2003 LS V6 (gen 2 car) that I bought used apprx 18 mos ago. I enjoy it a lot. It has 170K miles on it and I do most of the maintenance myself. So far, plugs, coils, engine management computer, brakes, & heater valve ... all per some excellent advice from members who post in this forum. Because I live in Alabama, I depend on the air conditioner almost year round. Yesterday, my wife reported the a/c had quit while she was on the way home. Since it was only a few months ago that the dccv failed and gave full heat in the cabin when she was expecting air conditioning, she has some experience with a/c failure on this car. Her report yesterday was that she was at interstate speed and running the a/c without incident when she heard a short low-pitched groaning type of sound and the a/c quit ... cabin fan still blowing but the air from the vents was no longer climate-controlled. It wasn't heated (like when the dccv failed) or cooled ... just ambient temperature. She turned the system off and drove home. Today, apprx 24 hrs later, I drove the car and the a/c worked fine. No problems. I've never had it checked or measured the temp from the vents but it seemed as cold as ever and plenty capable of dealing with the Alabama heat.

Does any forum member have any idea what might be causing the system to work intermittently? Based on other posts I've read, I'm guessing perhaps the compressor is failing and putting debris in the system, some of which might have temporarily clogged the expansion valve.

Is there an interim measure I should take or should I just continue to use the a/c system until it breaks completely? Obviously, I'd like to avoid replacing the expansion valve if possible.

Thanks in advance for your help!

 

[joegr]

It could also be that the AC clutch is failing.

 

[LeedsAL]

Thanks. Is there a way to determine that? Do you think I'm doing any harm to just continue to drive the car and use the a/c until something more definite happens?

 

[joegr]

If it is a compressor issue, you might be. On the other hand, all the harm may already have been done.
If it is the clutch, it will get worse and worse until you can catch it. The AC on my Ranger would work fine then stop. For weeks, it would never stop when it was home or I was in it to see what was going on. Finally, it did and I was able to see that the compressor wasn't turning. I measured to see that voltage was across the clutch coil. I tapped the clutch and it engaged. I took the clutch apart and removed one shim washer from it. It's been working fine since (at least a year now).

Of course, there are many other things that it could be instead. Look at the bottom of the compressor. If it is oily, it could be that has leaked enough oil out to start failing. The compressors on both on my LSes started leaking oil (at different times). Each time, I saw it on the garage floor (yellow/green oil) and replaced the compressors before they had leaked enough to start to fail.

You could also have some fault of the DATC, one of its sensors (like the evaporator temperature sensor), wiring, or the compressor clutch relay.

 

[LeedsAL]

Thanks joegr. Quick update ... compressor isn't oily and a/c has been working fine since my last post. I've decided to drive it until symptoms get more definite. Hopefully, it turns out to be a/c clutch as you described on your Ranger. Appreciate the help.