AC Runs Ice Cold Then Warm - Issue Repeats After Cycling the AC

[lammers_]

Hi All,

I've got a 2006 Aurion which is experiencing problems with its AC system. You turn on the AC, it begins ice cold. After approximately 15-20mins (sometimes even shorter) the air will become warm and you can smell a moisture smell in the cabin. If I turn the AC off and leave it for 1-2mins, then turn it back on again, the air is ice cold - the issue repeats and becomes warm again after some time, however continues to come ice cold again if I turn off the AC for several minutes.

The vehicle has been into my local workshop who re-gassed the system and put in a dye to see if there were any leaks. After returning the vehicle a week later and having it checked over again, there were no reported leaks in the engine bay space. Keep in mind, the issue is still present and doing the exact same thing as above.

The recommendation that I received was to replace the AC compressor, condenser and drier unit.

Having spoken to various other mobile AC specialists to see if any of them could shed some light, none of them have ever heard of this particular symptom in a vehicle before.

Has anyone out there in the community come across something similar to this? I'd love to hear your stories and/or thoughts on the problem.

Edited December 30, 2021 by lammers_
Grammar Correction

[KAA]

Hi Lammers, NO have never heard of this issue before which is by the sounds of it weird, so I am hoping some others can offer some advise which will help us all out in case it comes up again, it sounds almost like it is activating the heater side of the climate control system as it becomes hot, so hope someone can assist mate.

KAA

[lammers_]

Thanks KAA. Definitely a weird one!

I've been Googling all day and after finding several other forums discussing a possibility that the relay was the cause even though it tested okay, I decided to pop down to Repco and pick up a replacement relay for the Magnetic Clutch. Plugged it in, went for a drive with the AC on but unfortunately the same issue popped back up after 15-20mins.

Stumbled across the below though which sounds as though it might be a possible explanation behind my problem/s;

"If the AC blows cold and then the air becomes warm and after a while it becomes cold again then it suddenly becomes warm and this cycle keeps repeating it is most likely moisture in the system. The receiver dryer is designed to absorb moisture in the system. It can only absorb so much moisture after it has absorbed all that it can the moisture will circulate in the system. When it reaches the expansion valve at the evaporator the refrigerant will be at its coldest temperature it will freeze the moisture in the valve and the circulation stops. Then the air becomes warm, the warm air will eventually thaw out the moisture in the valve and the air will become cool until the moisture freezes in the valve again. Then the air becomes warm again. This cycle will keep happening until the source of the moisture is repaired and the receiver dryer is replaced and the system is vacuumed out with a vacuum pump."

Reference; https://www.quora.com/What-would-cause-my-car’s-AC-to-blow-cold-air-and-warm-air-at-random-intervals

At this point, I'm leaning towards just calling out an AC specialist and letting them do their thing because I'm starting to feel as though whatever the problem is, it's going to beyond me to track down and resolve.

[Sebastian Woodhouse]

I’m faced with a similar issue in my other car.  It’s likely to need a dryer, and the vacuum is done as part of the regas (well de-gas then replace part, then vacuum, then gas) process.

I would avoid compressor or condenser changed unless there is physical damage to them.  The Dryers are a finite life item (long life admittedly).