'01 XJ AC pulley engaging disengaging engaging disengaging

[ChrisD]

The wife's '01 XJ is acting very weird when the AC is on. In fact when it is on, the motor does some really funky things.

When you turn the AC on from the controls, the AC pulley engages for 3-5 seconds then disengages 3 -5 seconds only to re-engage for 3 - 5 seconds... goes on and on. At the same time the fan in front of the AC compressor turns on at the same time (on / off / on / off). Then at some point into this, the motor starts to shake weird.

My guess is the motor is to hot, therfore the system is forcing the ac to shut down. But the fan does not stay engaged to cool down the motor.

Any thoughts?

[nostaw]

Do you see a CEL?

By motor do you mean the whole engine?

I had my AC pump sieze on my '98 XJ in the spring a few years ago... Got no CEL. However, when I looked carefully at the pulley I could see when the clutch engaged the compressor didn't turn and the belt was slipping and really loaded the engine.

It is common to find issues in the spring w/ AC because many people don't use it in the winter and the compressor will fail because it doesn't turn for months and when it starts the lubrication isn't there (In the Sandens the lubricant is mixed with the coolant) and the bearings wear out suddenly.

The bad news is that it wasn't cheap to fix, and I got a refurbished one.

JW

[ChrisD]

The clutch does engage the compressor, but only for 5 seconds at a time. From what I have read this means your low on refrigerant and need a recharge. The weird shake is toward the front of the motor and happens when the clutch engages the compressor. Also I noticed that coolant (green in color) is spraying from the heater core area where the hoses connect. I wonder if that thermostat needs to be changed.

[ChrisD]

Update... the weird shake/noise is from the compressor also if you were standing in front of the XJ, the left line exiting the compressor gets cold and the right hand side gets really really hot. I wish I could locate a good overview digram on an 01 ac system.

[SteveB]

Chris,
I've had the same deal on both my 01XJ's, and never had decent AC either. Wish I had an answer.

-Steve

[nostaw]

The line into the compressor would come from the firewall area and should be cold -- that is the expanded coolant being drawn in. I think the dryer module is on the return side, but I'm not positive (looks like a cylinder... lines come in out, one on top & one low). The hot line is the output (compressed coolant gets hot) and should run to the condenser in front of the radiator.

It can't hurt to take it to a shop and get a pressure test. If all they need to do is top it off it isn't huge $, though I'm not sure why it would shake/vibe unless the compressor has an issue.

JW

[ChrisD]

I am going to have her bring it to the shop to have the pressure tested today. It is just weird that yesterday the compressor started making this noise, almost like extreme pressure was building an no where to go. When looking over the different components, I noticed a green liquid (perhaps coolant). The liquid appeared to be sprayed on the hoses in the area of the output line all the way back to the firewall and when you turn off the motor, you could hear some pressure being released.

[nostaw]

Maybe a clog in one of the pressure lines and the line finally burst?

The coolant in my AC which I've seen is kind of yellow, but they could make green (I don't know)...

JW

[DOUG]

Some vehicles use green refridgerant oil in the A/C system (Fords comes to mind). If you see it spraying out of a line, you just found your leak, which explains why the compressor clutch is cycling.
The system should be evacuated then pressure tested to locate the leak. Once the leak is repaired, the system can be evacuated and recharged with the proper amount of oil and refridgerant.

[ChrisD]

Doug - here is the thing, today the AC worked like a charm. However I am going to have the system recharged.

Thanks for the suggestions!

[ZAEDOCK]

However I am going to have the system recharged.

If you need a recharge, you have a leak.

[DOUG]

However I am going to have the system recharged.

If you need a recharge, you have a leak.

Exactly...