AC problem....

its a 1996 XJ.
Last week my AC wasnt blowing too cold. I started checking the AC stuff over, found the sight glass and it had lots of bubbles runing through it. I added one can of 134a to the system and now the compressor didn't keep turning on and off every 20 seconds, but it was still low. On the second can the compressor began to start and stop much rougher and would only stay on for a few seconds. When I checked the pressure in low side it was reading 20psi with the compressor off and 40 with the compressor on. The manufacturer of the refil kit says that at 70* ambient temp there should be 35-40psi in the low line so I didn't add any more. I let the engine run while I was cleaning up. Before I turned the engine off I checked the pressure again, this time it said there was 30psi with the comp off and 50 with it on. I took the gague of and looked at the directions again to see if I missed something, nope. Checked the pressure again and now it was reading 50off and 70on. I figured it was a good time to turn the AC off. I checked the low side pressure with the engine off, 80psi so I turned the valve to see what would happen. Only warm air came out till it hit 30psi then it started blowing a white liquid out so I turned it off immediatly. I turned the AC on again and within a minute the pressure with the pump on was at 60psi, more air came out.

Any idea what could be wrong, I did some searching but could not find anything like this, or is this the thing I have to bring it to a pro to get fixed?

~Alex

Started blowing out of where?

Saudade said:

Started blowing out of where?

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I opened the valve on the fill hose a little bit.

~Alex

I would suggest you take it somewhere before you break something or hurt yourself.

The pressure spec is with the AC running, fan at max, AC setting at "normal" (max but not recirc). It takes a few minutes for the pressure to stabilize. The gauges on those POS containers are just that. POS!. It's not just the low side that needs observing, it's the high side too.

With the AC off, the pressure in the low side and high side will equalize. It will read higher than the can specs out. Once you turn the AC on, the low side will get lower and the high side higher. How much lower/higher depends on a lot of things including the amount of refrigerant in the system.

If you feel up to tackling it, I suggest you "google" around a bit, get some decent gauges, some extra cans of refrigerant and some good safety glasses.

Do you think the system could be overfilled?

Without seeing it myself, that would be my guess.

According to the FSM, full capacity of the ac system is 32 oz. Since you put in 2 cans, you added at least 24 oz. Since the compressor did kick on, you were likely well above 8 oz of fill.

Alex, In rereading my earlier post, it appears to me I have have come off a bit harsh. It wasn't intentional. AC Systems operate at relatively high pressures and temps. It's real easy to hurt yourself so I get a bit cautious when I do it to my stuff and even more so when discussing it with others.

Saudade said:

Alex, In rereading my earlier post, it appears to me I have have come off a bit harsh. It wasn't intentional. AC Systems operate at relatively high pressures and temps. It's real easy to hurt yourself so I get a bit cautious when I do it to my stuff and even more so when discussing it with others.

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No offense taken, I've realized this is one of those projects I probably shouldnt havent tried myself. Yesterday the brass thread incert in the plastic housing blew out on me , I had an open can of 134a in one hand and a hose in the other.... fun times wrenchin on the jeep.

My local dealer treats me good, i'll probably bring this into them to check it out, since dumping alot of 134a into the driveway isnt a good thing to do.

Thanks for the help
~Alex

A/C is a complicated system, if you don't understand it you should not mess with it. FWIW, you can't diagnose the a/c system based on low side pressures, you really need a manifold gauge set.

IMO, it's not really that complicated. You just need to be careful and understand how the system works in order to service it. That's true regardless of the system (ign, fuel, charging, etc.).

IMO, it's not really that complicated. You just need to be careful and understand how the system works in order to service it. That's true regardless of the system (ign, fuel, charging, etc.)

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I agree.
Im speaking in generalities, if you know nothing about a/c systems (which can be concluded that he doesnt), they seem complicated. Im ASE and Jaguar factory certified in a/c systems so i dont think its comlicated either

I went to a local garage today and discribed the problem and its symptems. They said it is most likley a clog in the system and they can put a vaccume on the whole system (60psi) and suck everything out then refill and check for leaks.

~Alex