[CeeBee]

I’ve ran across a lot of threads about the a/c not working when idle but cold when moving, but my issue is baffling me. The A/C on my 2012 Kia Optima EX works fine while moving- it will feeeze you out even on a 90 deg day- but blows warm when sitting still. The ac compressor and fan are both on during the warm air and the charge has been checked and is correct. The air will start getting cold if I keep the engine revved and the rpm’s at approx 2,000 or higher without ever moving the car, so it isn’t an air flow problem either. My mechanic thinks it might be the solenoid inside the compressor but isn’t sure. The dealership was no help at all. They had no clue and wanted to replace the whole system. Before I spend the money replacing the compressor, is there anything else that could cause this? I have been able to recreate the a/c getting cold but keeping the rpm’s up every time.

 

[Turbonut]

I've always maintained that the electronic control valve (@ $30) in the VDC has become faulty, but have seen a few replace the valve and end up needing a new compressor to correct the problem.
Now was it a faulty replacement valve or was it actually the compressor internals that were deficient, don't know? Problem is that with either repair the entire system needs to be discharged.

If at idle for a period of time, some turn the temp down to create the needed cold air flow, but on our '11 2.0T, it was an easy decision as the A/C went from a delay on startup for 5-10 minutes, to a 90+ degree day when the cold air stopped completely. Wife's mandate, fix the A/C or use her car, so the next day Installed a used compressor (23K miles $60) and it's been fine for the last 3 years.

Here's some information, probably more than we want to know:

Diagnosing Variable Displacement Compressors | MOTOR

In earlier air conditioning systems, the compressor ran at full capacity whenever its cycling clutch was engaged. If the engine was running and the clutch was engaged, the compressor was pumping. And the faster the engine turned, the more pressure the compressor developed. The only way to...

www.motor.com

 

[CeeBee]

Thanks. I guess I’ll bite the bullet and replace the compressor. I can’t really complain too much as this is the first thing I have had to replace besides normal maintenance and it is at nearly 200k.

 

[Adrian A.]

Thanks. I guess I’ll bite the bullet and replace the compressor. I can’t really complain too much as this is the first thing I have had to replace besides normal maintenance and it is at nearly 200k.

Did replacing the compressor solve the problem? my 2013 EX currently has the exact same issue where when i press the AC button, i can hear the aux fan come on but no cold air. Then when i bring up the revs to about 1.5-2k and hold it there eventually about 10 seconds i will feel the compressor finally kick in and cold air will start blowing again. It will blow cold for the rest of the drive and if the car has been off for only a short time. After a day or so, the same problem returns.

 

[CeeBee]

It does sound like what mine is doing, but due to the cost I have not replaced it yet. I am putting it off until spring in case I decide to trade the car off.

 

[Adrian A.]

It does sound like what mine is doing, but due to the cost I have not replaced it yet. I am putting it off until spring in case I decide to trade the car off.

what do you do to get the cold air going again? i’m going to take mine in next week to an AC specialist and see what they think.

 

[Turbonut]

Compressor runs all the time even if A/C is off. The valve at the rear of the compressor changes
a plate inside to increase/decrease volume as needed. I had stated previously, because of a noisy
compressor I did a replacement with a used compressor @ 3 years ago and this summer the
valve gave out, no air at idle, so replaced the valve and all was good again.

 

[Adrian A.]

The AC shop i took it to finally fixed the issue, at first they thought it had something to do with the aux fan at first but they replaced what they told me was a sensor that tells the compressor to start running. Blows cold every time even after a cold start now!

 

[Turbonut]

Reply

The AC shop i took it to finally fixed the issue, at first they thought it had something to do with the aux fan at first but they replaced what they told me was a sensor that tells the compressor to start running. Blows cold every time even after a cold start now!

Know it's difficult if you're not familiar with the system, but the compressor runs all the time, so what did they replace, the control valve?