AC Purged Itself

[bunz559]

The other day my 2003 V8 was idling in my drive way with the AC on full blast. I had just driven it around town and it had been idling for about 5 minutes. All the sudden a loud quick purge came from the engine bay and a cloud of smoke or dust came from underneath the runner. 1 minute later, it purged itself again. I checked the air blowing from the vents and the air was barely cool. The dust or smoke smelt very much like R134 refrigerant. Haven't looked into it just yet as I was just loading to head out of town.

Any experiences or ideas of what to check? I figured a leak would be first to be checked, but I've never experienced a system purging itself. What may cause this? Temps outside was roughly 100+ and I just had the AC system refilled at a shop 2 weeks prior.

 

[keakar]

The other day my 2003 V8 was idling in my drive way with the AC on full blast. I had just driven it around town and it had been idling for about 5 minutes. All the sudden a loud quick purge came from the engine bay and a cloud of smoke or dust came from underneath the runner. 1 minute later, it purged itself again. I checked the air blowing from the vents and the air was barely cool. The dust or smoke smelt very much like R134 refrigerant. Haven't looked into it just yet as I was just loading to head out of town.

Any experiences or ideas of what to check? I figured a leak would be first to be checked, but I've never experienced a system purging itself. What may cause this? Temps outside was roughly 100+ and I just had the AC system refilled at a shop 2 weeks prior.

it has a high pressure release valve on the compressor and it definitely sounds like that is what happened.

check if your fan clutch might be bad on the engine, if airflow stopped being pulled through the radiator it causes a/c pressures to rise quickly and could trigger the pop off valve. that is what it is designed for, so you dont blow the seals out of have a hose burst.

you need to solve the question "why" pressures went up high enough for it to open. its not something that could ever go off by accident and i have never ever heard of one just going bad.

as you obviously know, you will need freon levels checked "after" you solve the puzzle as to what caused something to drastically change pressures in the system

 

[First 4Runner]

it has a high pressure release valve on the compressor and it definitely sounds like that is what happened.

check if your fan clutch might be bad on the engine, if airflow stopped being pulled through the radiator it causes a/c pressures to rise quickly and could trigger the pop off valve. that is what it is designed for, so you dont blow the seals out of have a hose burst.

you need to solve the question "why" pressures went up high enough for it to open. its not something that could ever go off by accident and i have never ever heard of one just going bad.

as you obviously know, you will need freon levels checked "after" you solve the puzzle as to what caused something to drastically change pressures in the system

Maybe the AC shop put too much refrigerant in? Wouldn't that cause high pressure?

 

[keakar]

Maybe the AC shop put too much refrigerant in? Wouldn't that cause high pressure?

possible, yes, but i would think it would have most likely purged right away the first few times you used it in this heat



OP you need to bring it back to the shop and tell them what happened and insist they check it at no cost, speak to the manager if need be

either way you need to know what caused it

 

[bunz559]

Thanks Keaker. Appreciate this info. I searched Google with some return but not a whole lot of information. I will most definitely check the clutch fan. That seems to be what some folks suggest to do and describe as a culprit to the system purging itself.

 

[alia176]

I need a little education here, if I may. Our A/C system has a trinary switch which I *think* tells the a/c comp to run/stop based on the system pressure. If the system pressure became too high, this pressure switch should have stopped the compressor from running, in the hopes of lowering the system pressure down to an acceptable level.

Are we saying that the a/c comp kept running even though the system pressure went too high? At least that's what I gleaned from reading this thread. So, perhaps there are more than one issue?

- why didn't the pressure switch stop the a/c comp from running and over pressurizing the system? In another words, the a/c comp kept running even though the system pressure was reaching critical level so much so that the purge valve had to release pressure.

- why did the system pressure get so high? Is it due to the condenser not cooling enough, as mentioned already. A/C condenser sits in front of the radiator. Perhaps the air flow decreased due to radiator fan not pulling enough air through the condenser? This would point to the radiator fan clutch malfunctioning.

Looking forward to solving this riddle!