AC blowing hot. Compression kicking on and off. Freon charged.

[McFudden]

So I’ve got a 2002 Ford Explorer XLT with 172,000 miles on it. The engine was remanufactured and has about 10,000 miles on it, with a transmission not just rebuilt but replaced with reinforced spacers and plates. It runs great, doesn’t leak oil, and the 4x4 is smooth as can be. Here my issue; the AC isn’t cold. I’ll admit, I’m not the best HVAC guy. Last 4.0 inline six ford product I had was an 83 F150 in northern Maine, so AC not only wasn’t an issue, my truck didn’t even have it. I’ve done all the minimal trouble shooting I know; turned the Max AC with the blower on high and getting hot air and listened to hear the compressor kick on and the engine load. Not only am I hearing it kick on, I’m heading it kick back off moments after. I further verified by opening the hood and watching the clutch engage and disengage. From the little I know, this usually means the system is empty and needs to be charged. So I got a kit. I tried to charge. It took a teeny bit, and then the same issue, the compressor engages and disengages and won’t draw. More importantly I show no reading on the pressure gauge. I then took a pocket knife and depressed the valve for half a second and Freon escaped so the system appears to be charged. So I’m lost. The compressor is engaging but not staying engaged, System is pressurized so a leak is unlikely, but no cold AC. Any ideas?

 

[TechGuru]

Clogged orifice screen may be causing over pressure cut off.

 

[McFudden]

Update: it actually was low on Freon aaaaaand my gauge is broken. I’ve got a small leak. Now, here’s my new problem; when the AC kicks on my RPMs are dropping waaaaaay down. It’s not stalling but it’s coming damn close.

 

[Mbrooks420]

4.0 inline 6?

If it idles fine, and has no drivability issues I’d suspect a compressor problem.

 

[McFudden]

Idles fine with the AC off, even idles okay when the AC is on but it’s not terribly hot out, but when the AC is working hard, at an idle the RPMs drops out. It drops down to like 500 and tries to choke out but she won’t die. I figure it’s the compressor. I also figure my AC system has a small leak because I just filled it a few days ago and it’s already “frosting” when I first kick it on which is usually a sign of low Freon. My question is WHAT is going on with the compressor considering that the clutch seems to be working fine. It is kicking on an off a little faster than it should. I’m wondering if it’s that low on Freon already and that’s it, or if I’ve got another issue, because I can’t see why low pressure would drop my idle that much. That’s what the pressure cycle switch should do, when the pressure drops it should lower the idle, but what would make it drop so far?

 

[domct203]

If you have a leak your compressor is cycling because you are low on Freon.

I have the same issue, I charge the system and it will be fine for a few weeks, but then I’ll notice that the air is no longer blowing very cold, and my compressor is cycling. If I fill the Freon again the compressor cycling stops.

Idle always seems fine though.

I’m also curious about the ‘4.0 inline 6’ comment. Your explorer should be a V6.

 

[Turdle]

You might clean the IAC to take care of the dripping idle issue

How to: - IAC valve cleaning thread (w/pics)

 

[MrPulldown]

your blend door actuator can be dead. I figure if you the temp set for cold and the AC isn't working, you should be getting outside temp air, not hot air.

I too am having AC issues and just starting to learn.

 

[MrPulldown]

Update: it actually was low on Freon aaaaaand my gauge is broken. I’ve got a small leak. Now, here’s my new problem; when the AC kicks on my RPMs are dropping waaaaaay down. It’s not stalling but it’s coming damn close.

So did the unit start blowing cold once you got enough freon in there. I added some to my system yesterday. Got the compressor to kick on. But it is still not clod.

 

[firefly1246]

Add some UV dye to the system. If you have a manifold set then you can pour some into the input hose before you put your next can of refrigerant in. If you don’t have a manifold set (if you plan to fix the leak yourself you will need one and a vacuum pump) then get a can with dye and refrigerant. After it leaks out again use a black light to find the leak.

One thing to also note if the clutch keeps disengaging, is to check the clutch gap with feeler gages. Look in the manual but I think it is supposed to be a max of .030” or something close to that. There is a shim washer and you can remove it or grind it thinner to get the gap correct. This was my problem a couple years ago at ~235k on the original clutch/compressor.

Please don’t put in stop leak, that crap will screw up your system.

-Scott