A/C Spewing steam and green

[99Qx4GroundUp]

Hey gents,

I'm now focusing on my A/C problems for the 99 Q. Unfortunately I have only a little knowledge on the subject.

I recharged my A/C with A/C Pro and it lasted my trip to Austin for the weekend, but by the time I got back home about 3 days and 500 miles (round trip) it started spewing steam from somewhere under the hood... It's typically about 100-105 degrees out here after June, so the need to fix it is urgent...

The first time I noticed it, I was inside the car with the sun shade up sitting in the parking lot on my lunch break eating. I heard a large leak sound coming from the brake pedal. My ABS light is on so I thought it was my brake booster freaking out. I pressed on the brake and the leak stopped. I looked at my Temp Gauge and I was 3/4 the way to HOT. Typically I stay right below halfway... So I popped my hood and looked on the ground for coolant. Saw none, then I noticed that there was a LOT of green refrigerant on the drivers side of the engine bay.

Questions:
I am assuming that there is a large leak in the A/C line?
Why would it not constantly leak?
Does a bad Expansion Valve cause this?
Any other ideas?

Thanks

Javin

[ipeelscats]

Does your ac still work? I am assuming it does not. The green substance was most likely UV dye that someone injected to locate a leak at some point. Refrigerant is not burned by the system, if it is low you have a leak. You probably dropped your entire charge at one time. Those DIY recharge kits don't always give you a correct charge. You should get the system leak searched and recharged by a professional. The temp gauge reading high is likely a separate issue ( low coolant, air in the cooling system etc). These are not definite answers, just guesses based on the information provided.

[99Qx4GroundUp]

The A/C still works. I blows cold when I recharge it. I'm thinking that it had too much pressure in it. I just used the A/C gauge to drain all of the pressure out of it down to 0 Psi. Almost ZERO refrigerant came out of it.. I recharged it with more refrigerant to get the gauge in between green so I hope that I or the previous owner just added too much. It is blowing ice cold for now so I will update this thread in a week or so to let you guys know if I'm alive or not, and if the problem came around again.

Thanks for the input,

Javin

[ipeelscats]

it is illegal to vent refrigerant to the atmosphere. When you brought the system down to 0psi, you most likely got air into the system. You really should have the system looked at by a professional. There should be no air inside the system. They are put into a vacuum before they are charged to prevent this.

[99Qx4GroundUp]

Oh, wow. Good to know... I'll vacuum it next time...

Thanks.

[ipeelscats]

Good deal. Air can cause refrigerant pressures to run much higher than they normally would. Hopefully your issue is solved for now. Good luck and stay cool.

[nalz]

I have another possibility for you. Maybe the hotter-than-normal temp gauge and the "steam" are related. If the airflow through the radiator and a/c condenser are inadequate for the ambient temp and heat currently being generated by the engine, then the gauge is going to read hotter, and the high-side pressures on the a/c system are going to climb, possibly high enough to purge the excess through the pressure relief valve. The one time I witnessed this, I saw a large whitish cloud envelop the whole engine compartment. I thought it was steam initially, until realized it did not have the typical sweet smell of antifreeze. Soon after, I became aware of a drop-off in a/c cooling performance. The pressure relief valves are usually located on the a/c compressor, so I would look over that area carefully and see if the green discharge pattern jives with the location and orientation of the valve. Off the top of my head, the component that could cause an inadequate airflow condition is the radiator fan clutch, or an a/c condenser coated in bugs, hay, feathers, etc,, or with a lot of bent-over cooling fins, from pebble strikes

[99Qx4GroundUp]

I have another possibility for you.

What you described is a lot like what I am experiencing. The car only ran hot while I was parked and idling, when I began to drive, the temperature gauge went down almost immediately.. Do you think I should replace the Compressor? It hasn't done it to me since i purged the pressure, but my A/C has not been as cold as it should be with a large canister charge. It is "cool" but not close to cold... I am thinking I have a small leak somewhere, I'll look into that soon. It's **** hot here in Texas... 104 today.

I'll have a new fan clutch and blade in by Friday, I know that that isn't working as well as it should. I don't have a radiator shroud either, with how often I was working on it, it wasn't of use to me and it got misplaced in a move.

Javin

[nalz]

I meant to get back to you earlier, but in an attempt to get better info, I was trying to contact a guy I knew who was an Acura tech and had, at one time, owned a 98 Pathfinder. Also, I know you have an Infiniti QX4, but there's a decent chance it and the pathfinder have similar if not the same parts. He made me aware of a high/low pressure switch that's mounted to the top of the "liquid tank", an a/c component located in front of the battery. This switch will shut down the a/c compressor clutch if pressure falls too low, or if it's too high( to prevent damage to the compressor, and to prevent the dumping of refrigerant into atmosphere, thru the pressure relief valve). That means that for the green and steamy discharge to have come from the pressure relief valve, it would mean that the high/low pressure switch was already bad, a good switch should have turned off the compressor and prevented the high pressures. You asked if the compressor needed replacing: not at this point. You really need to find the source of refrigerant oil, whether it was a limited release from the relief valve or a ruptured a/c hose or seal. It may help to buy a UV/black light and special googles that were originally intended to be used with the dye in refrigerant oil, such as : https://www.amazon.com/Uview-413010-Bat ... B000NBWCFC