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AC compressor clicking


New Member
Mar 23, 2014
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Looking for some advice. I have a few questions, all AC related. It will be a little long winded, so I thank you if you make it all the way through.

The compressor on my 2002 Ranger (175K miles) has a steady clicking sound when the clutch is engaged and the truck is at idle. When I rev the engine, the clicking seems to stop until I let off on the throttle and it will start clicking again as the RPM's come down and continue while idling. This doesn't seem normal and I wonder if it is a sign of trouble to come. I checked the air gap at the clutch and it is around .035. This is a little high according to spec, but not sure if it would cause this clicking sound.

Everything seems to be working fine. The AC is literally ice cold. I checked center vent with an infra red temp gauge and it got down to 31 degrees. The accumulator shows around 24 degrees. This was when the outside temp was around 65 degrees. Also, my pressures at idle were 28 PSI low side and 140 PSI high side. The compressor never cycles, just stays on the whole time. It just stays on continuous, both on normal AC and max AC. Question here is is it working too good. Should it get that cold? Shouldn't the system cycle? I would think the evaporator would ice up like this.

Should I have the system flushed? With the high mileage I have, I have heard it is good to flush the system. I just don't want to flush the system, and then have to replace parts afterwards that should have been replaced beforehand due to issues described above or below.

To complete the history here, I thought the AC wasn't working quite up to par. I connected an AC recharge can to the low side and the gauge on it kept dropping below 20 PSI and the compressor would cycle. I added more freon, but it didn't seem to affect the low pressure. I finally got enough in to where the compressor stopped cycling and the pressure was 25-30 PSI on the can gauge. I ended up adding 2 12oz cans plus partials from two other cans. I made two mistakes here. First I didn't use my manifold gauges and trusted the can gauge. Second I didn't look to see how much freon it should take and I now know I over filled it. I then went on a long drive (6 hours) and the AC worked fine. The next day, drove for about 30 minutes, then went into a store. Maybe 5 minutes later, came back out and the truck would not idle. Seemed like something was dragging down the engine. I turned off the AC at the dial, but that didn't affect the problem. I drove it about 10 minutes, but it still wouldn't idle. I opened the hood and notice green colored liquid by the AC compressor (one of the cans I added had dye in it). I waited about 30 minutes, started the truck up and it ran fine. The AC came on and worked fine as well. I figured the AC system purged due to over filling, but I don't know why the truck wouldn't idle. It was like the clutch stayed engaged the whole time it was purging, even with the switch of. The high pressure switch should have prevented the clutch from engaging also. Any insight here would be helpful, just to ease my mind.

Thanks for reading all the way through. I didn't want to put in separate posts in case all of the information was pertinent to one common problem.

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