Kia Optima Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
So I originally had a problem with it blowing hot air, but I just put in refrigerant and it’s nice and cold. About a week later and it is starting to blow really weak. Any idea what it might be?
 

·
Registered
2011 Kia Optima
Joined
·
3,604 Posts
Thought I was going to read about A/C not cooling when first started but after 10-30 minutes it's fine, but his is different........I think.

First, did you check to see if the refrigerant was low before adding the R134A?
Second, if not, you'll need to have gauges put on the system to see the charge.
Third, with the VDC (variable displacement compressor) it doesn't operate the same as a clutch type compressor so values change.

If static charge is high, meaning normal @ 80psi, I've seen higher, then there is probably a problem with the operating system. If it's low, naturally there is a leak and that would need to be found.
Must say that these systems are pretty robust in that most of the inefficiencies from the A/C system stems from the control valve at the rear of the compressor failing. When that fails one can see no cooling, low cooling, or delayed cooling.
 

·
Registered
2013 Kia Optima
Joined
·
562 Posts
I have a 2013, and it blows weak when you first start the car, and it is at idle. It blows cold when you get going, and is fine until you shut down for a while and then restart. My guess is that the A/C pump doesn't work efficiently at lower RPM, and the engine must be running at driving RPMs for a few minutes to build up system pressure to the point it can blow cold air.

It's really more of a quirk than an inconvenience.
 

·
Registered
2012 Black SX Prem. & Tech.
Joined
·
2,294 Posts
Now I'm wondering, How do we check if our A/C is working at its best?

I have a good thermometer, so maybe there is a procedure to run at max cold settings and you should see X temperature drop?

Like, how do you know when it's time to service the A/C? Maybe you could get even better performance than you have, but just got used to it and forgot how good it used to be at first?
 

·
Registered
2011 Kia Optima
Joined
·
3,604 Posts
Warm weather is here and guess we'll hear more problems with no a/c at idle, delayed start, etc.

Replace electronic control valve at the back of the compressor and you'll be fine. The part is @$30 but the system needs to be discharged, replace part, evacuate, charge 19.4 oz refrigerant

People we know from the AA ball park told me after the fact, their 2013 SXL had the problem, took it to he stealership and they replaced the compressor, fixed the problem but cost them $1150.

Years ago mine would take sometimes 10minutes or even longer to get started, but fine after that until one day we went shopping, a couple of stops, great a/c, then I waited for the wife at Walmart......
When we left , no a/c, and nothing on the way home on a humid 95 degree day. The ultimatem came down, fix the a/c or that's the last time I'm riding in the car as we'll take mine. Next day installed a used unit from a Sonata with 23k miles, been fine ever since.

Only reason I installed a used compressor and didn't replace just the valve, was at 115k miles it was noisy, so killed 2 birds with 1 stone, no more noise and cold air.


Thought I'd add a reply to KF, no service needed as it's a closed unit, so if a leak, problem with system. I'll need to find charts in the garage that will give approximate vent temp at a specific ambient temp, but off the top of my head not certain.
 

·
Registered
2016 Optima LX
Joined
·
1 Posts
So I originally had a problem with it blowing hot air, but I just put in refrigerant and it’s nice and cold. About a week later and it is starting to blow really weak. Any idea what it might be?
You can try adding coolant with leak test in it. You will see the color come out wherever the leak is. You have to be careful adding your own freon. If you add to much or to little oil you can damage your ac which will cost more in the long run. Good luck

The other thing is purchase for around $25 the ac refresher kit from dealership. It consists of 2 cans with instructions on cans. The larger can is a spray foam you spray into the drip line (which cleans the evaporator), pinch it off, let it sit for 10-15 minutes then drain. The smaller can kills mold and mildew in the air intake and air vents. If you have a funny smell from ven you s that's typically why.
 

·
Registered
2011 Kia Optima
Joined
·
3,604 Posts
You can try adding coolant with leak test in it. You will see the color come out wherever the leak is. You have to be careful adding your own freon. If you add to much or to little oil you can damage your ac which will cost more in the long run. Good luck
Maybe you could explain how to do a leak test in a HVAC system by using coolant?
I'm all ears!
 

·
Registered
2018 Kia Optima
Joined
·
1,166 Posts
LOL I think he meant to say refrigerant...that would be a very interesting leak test to attempt using coolant.
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top