I have a 2015 Kia Optima EX (regular gas, not hybrid and not turbo). I need to replace the condenser, the a/c expansion valve, and the electronic control valve for the a/c compressor (this can does not have a traditional "a/c clutch"). One of these three things is causing my a/c to work only intermittently. My plan is to take it to a shop and have them evacuate the coolant. This will pull all the coolant and compressor oil out of the system. After that, I plan to drive it home (won't turn the a/c on) about 20 miles. Then, change out the parts listed above. Lastly, drive it back another 20 miles to the shop where they'll do a vacuum and test for leaks before recharging the system with coolant.
My A/C compressor is connected to my serpentine belt, so the pulley on it is always spinning whether the compressor is on or not. I'm worried that after evacuating all the coolant and a/c oil, the compressor itself will be spinning with no lubrication. Then, I could damage the compressor itself while I'm driving it back and forth. Do I have this right? Will my A/C compressor be damaged if I do this?
There are different types of Variable Displacement Compressors.
Yours has no clutch on it so it's an ECVDC (Externally Controlled Variable Displacement Compressor) ((direct drive)). The computer is providing a pulse width modulated electrical pulse to a solenoid in the compressor which controls the displacement.
But even when the computer isn't energizing the solenoid at all the compressor is still pumping refrigerant (a little).
So to answer your question, you may be able to get away with driving 20 miles without any refrigerant in it but I wouldn't risk it.
The pulley on your AC compressor turns all the time, but there is an electronically-controlled clutch between the pulley and the compressor - you wouldn't want the compressor to run all winter!
When you evacuate the refrigerant from an AC system, the lubricant that is in with refrigerant stays in the system - unlike the refrigerant, it does not turn into gas at normal temperatures.
That's interesting. I know the compressor takes Peg 46 oil. So when the mechanic evacuates the system, he's really removing gas, not the liquid oil? Do I have that right? What I'm trying to avoid is replacing all these AC parts, then blowing up my compressor because there's no oil in it to provide lubrication when the pully spins on it.
you wouldn't want the compressor to run all winter
Actually you do, to keep the compressor and seals lubricated. It also aids in defogging windows. Vehicles with automatic climate control run the compressor all the time and adjust temperature using the blend door. On vehicles that don't automatically run the compressor all the time the owner's manual will recommend turning the AC on periodically even during the winter.
When you evacuate the refrigerant from an AC system, the lubricant that is in with refrigerant stays in the system
Correct, when evacuated under controlled conditions. You do lose oil with a sudden refrigerant loss like a hose bursting.
there is an electronically-controlled clutch between the pulley and the compressor
That's the question. I would hope there's something like that internally that's part of the control valve's operation that would prevent damage due to lack of refrigerant. (What if your condenser is punctured by something while driving and the system self-evacuates? Will your compressor be destroyed?) However I honestly do not know the answer to that, having never dealt with a clutchless compressor. Scotty probably knows.
It might also be a good idea for the original poster to ask in a Kia forum or an AC forum.
you wouldn't want the compressor to run all winter!
You would. Using the windshield setting on your HVAC unit, automatically turns on the compressor and all air is routed through the evaporator core before the heater. And for good reason . #1 it takes a lot less energy to heat dry air, and #2 you wouldn't want a bunch of of moist air hitting a cold windshield.
Also, what Chuck said. Lack of use kills AC systems. My friend thought he was smart so he somehow disabled his AC system. Then when summer heat came and he wanted to use it, he couldn't because it failed.
