# AC evaporator froze solid



## Snipesy (Dec 7, 2015)

Drain is clogged or its low on refrigerant.

A properely working A/C system will not freeze however if its low there just isn't enough mass to prevent freezing as the gasses expand and cool further.

It should also switch between recirc and outside air on the fly for efficiency automatically. For some reason GM allows people to disable that so make sure you aren't doing that.


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## snowwy66 (Nov 5, 2017)

Clogged drain. Wrong or improper cabin filter. Expansion valve. Are other possibilities also.

Need to know what your hi and low pressures are doing. With motor at 2000 rpm.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> Drain is clogged


Drain works fine. This past week we were on vacation in Kentucky during a very hot & humid spell and the AC running in a convenience store parking long was draining a lot of water. It's running clear without any clogs.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> It should also switch between recirc and outside air on the fly for efficiency automatically.


My AC has manual control over recirculation. I turned it on because it was so humid outside that straight air blowing through the cabin was still noticeably moist.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> Clogged drain. Wrong or improper cabin filter. Expansion valve. Are other possibilities also.
> 
> Need to know what your hi and low pressures are doing. With motor at 2000 rpm.


The cabin filter is the proper one. I replaced it myself.

I'll take it to the Chevy dealership on Monday to see what they can do because I don't have a gauge set to see what pressures are doing.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> A properely working A/C system will not freeze


It's $160 to evacuate the system and refill with refrigerant that has the UV leak detection stuff. Dealership service writer suggests run it some more and see if it's a one-time thing or maybe getting worse. 

To be clear, it was a combination of circumstances: an extremely humid day, we were cranking along at highway speeds so the compressor was pumping steady with lots of airflow over the condenser, and we had the interior fan on notch 6 of 8 because we were driving into the sun and wanted lots of cold air blowing on us.

I'm going to let it go a few weeks to see what happens before I throw money at this problem.


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## snowwy66 (Nov 5, 2017)

Shops buy the 30 lb cylinders.

I buy the 30 lbs. 

They all come with oil and the oil contains the uv.

The only time my fan sees speed 4 is when the car sits in 100+ degrees. Most of the time it's 3. Or lower. And I NEVER use recirculate. But I'm in the dryer west coast air.

It drives me nuts to use hi fan speed.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> The only time my fan sees speed 4 is when the car sits in 100+ degrees. Most of the time it's 3. Or lower. And I NEVER use recirculate. But I'm in the dryer west coast air.
> 
> It drives me nuts to use hi fan speed.


It's hot here in the Midwest, and HUMID. Air so thick you can feel it clogging your lungs on some days.

When it's humid enough, the air coming straight into the car isn't dried enough. You can still feel it is a little bit clammy. That's when you want recirculate on so you can get about 90% of cabin air (I think about 10% of the airflow is fresh air from outside) and get that air really dehumidified.

We want that fan on about stage 6. I think 7 and 8 make more noise without much more cooling, so 6 is the highest I usually go. I use 8 if the car has been parked and I'm starting it to walk away for a few minutes while the passenger compartment cools down a bit.


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## Snipesy (Dec 7, 2015)

snowwy66 said:


> Shops buy the 30 lb cylinders.
> 
> I buy the 30 lbs.
> 
> ...


Even the OEM refrigerants are suppose to have UV dye now from factory.... But I have not seen it personally yet.


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## snowwy66 (Nov 5, 2017)

Snipesy said:


> Even the OEM refrigerants are suppose to have UV dye now from factory.... But I have not seen it personally yet.


They do.


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## snowwy66 (Nov 5, 2017)

Barry Allen said:


> It's hot here in the Midwest, and HUMID. Air so thick you can feel it clogging your lungs on some days.
> 
> When it's humid enough, the air coming straight into the car isn't dried enough. You can still feel it is a little bit clammy. That's when you want recirculate on so you can get about 90% of cabin air (I think about 10% of the airflow is fresh air from outside) and get that air really dehumidified.
> 
> We want that fan on about stage 6. I think 7 and 8 make more noise without much more cooling, so 6 is the highest I usually go. I use 8 if the car has been parked and I'm starting it to walk away for a few minutes while the passenger compartment cools down a bit.


My personal experience from I've been seeing with ac. And I've been playing since 1988.

Weak ac. Same with heater. Cold thermostat. 

Mine is fully charged according to new epa guidelines. Done last year.

I don't need a high fan speed. Same with heater.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> Weak ac.


I never had a problem with the AC being weak. I bought a GM product because they make the best AC (they founded and owned Frigidaire for 60 years). The AC blows very cold, and a huge volume of air like I enjoy it.



> I don't need a high fan speed.


Oh GOD, I absolutely do. I close the vents on the passenger side and crank the AC to coldest temperature setting and fan speed of about 4-6.


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## jimmyc (Jun 27, 2020)

Keep the fan on "high".


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## Ma v e n (Oct 8, 2018)

I love high speed fan. LOL. 

The Cruzes problem is that the condenser heat soaks at idle, because of the jet hot mf'in turbine 6" behind it. LOL. The fan is too small and the engine bay too tight to evacuate heat when stopped. That's when AC can't keep up, while in motion that sh!t is ICE cold.


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## Snipesy (Dec 7, 2015)

Meanwhile I set it to 72F auto because anything else is too loud or too cold.

Now I also wear sweatshirts in 80 degree weather so.


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## WillL84 (Aug 5, 2019)

Snipesy said:


> Meanwhile I set it to 72F auto because anything else is too loud or too cold.
> 
> Now I also wear sweatshirts in 80 degree weather so.


Mine is set to 72 all the time as well, auto fan unless I need the defrost/defog for the windshield. 70 seems way too cold and 75 feels way too hot lol


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## Barry Allen (Apr 18, 2018)

So, here is something beautiful. I found a TSB on this problem:

*#18-NA-260: Air Conditioning (A/C) Not Cooling, A/C System Low or Empty of Refrigerant
August 23, 2018 (updated March 14, 2019 to add model year 2019 vehicles to the TSB)
Condition: Some customers may comment on the A/C not cooling. Technicians may find the A/C system being low or empty of refrigerant.
Cause: This condition may be caused by the A/C refrigerant leaking from the A/C condenser plug.
Correction: Perform an A/C system leak test to verify that the leak is coming from the A/C receiver and dehydrator plug. If there is a leak coming from the A/C receiver and dehydrator plug, replace the plug.*

I took this TSB to the dealership and basically asked them to do me a favor to see if we could resolve this. I was asking if they could check if that's where the leak is (if there is a leak) and if so, see if we could get this issue resolved for a reasonable cost. Their quote was $320 to evacuate the system and recharge it with 1 pound of refrigerant. I can only imagine what the repair cost is to replace the plug if it's leaking. Maybe someone could give me an estimate on that?


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> So, here is something beautiful. I found a TSB on this problem:
> 
> *#18-NA-260: Air Conditioning (A/C) Not Cooling, A/C System Low or Empty of Refrigerant
> August 23, 2018 (updated March 14, 2019 to add model year 2019 vehicles to the TSB)
> ...


R1234 is super expensive. Check sticker under hood near fan for refrigerant type and capacity info.

If R1234 you can find an independent shop to retrofit the system to R134. It’s not illegal...Yet... But it is significantly cheaper.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> R1234 is super expensive. Check sticker under hood near fan for refrigerant type and capacity info.
> 
> If R1234 you can find an independent shop to retrofit the system to R134. It’s not illegal...Yet... But it is significantly cheaper.


It is definitely R-1234yf. I have seen the sticker under the hood.

If retrofitting, I could possibly do it myself and charge it with R-290 (propane) from a BBQ bottle. I've done that before on other cars I've owned.

Filling it with any refrigerant doesn't fix the problem of the leak, though. If it's a slow leak that I could live with, I'd just retrofit and top it off once a year with R-290.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> If R1234 you can find an independent shop to retrofit the system to R134. It’s not illegal...Yet... But it is significantly cheaper.


Also: retrofitting is illegal. The EPA considers it tampering in violation of the Clean Air Act and the fines are huge.


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> Also: retrofitting is illegal. The EPA considers it tampering in violation of the Clean Air Act and the fines are huge.


You just can't make new products with R134. Beyond that there's nothing for at least the next 4 years. And R1234yf systems are about 95% compatible with R134... Just don't blend the two.

You're probably thinking of the old school refrigerants. Yeah using those is a big no no. A blend of propane will work but there's a very explosive reason on why it's banned from automotive.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> You just can't make new products with R134. Beyond that there's nothing for at least the next 4 years. And R1234yf systems are about 95% compatible with R134... Just don't blend the two.
> 
> You're probably thinking of the old school refrigerants. Yeah using those is a big no no. A blend of propane will work but there's a very explosive reason on why it's banned from automotive.


You can make new products with R-134a. There is no ban on it, but manufacturers get credits for using refrigerants that have low global warming potential.

R-290 is flammable, not explosive. It's not banned per-se, but just not widely adopted for the flammability reason.


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## snowwy66 (Nov 5, 2017)

Some of you should read the latest manual on refrigerant. 

The required reading to pass certification if you want to continue buying freon more then 2 lbs.


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> R-290 is flammable, not explosive.


In the container under controlled release. Sure.


If you’re talking about the sticker on the side of the container which just says flammable... Yes they are highly misleading.


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## Barry Allen (Apr 18, 2018)

An independent shop did a quick check with UV light and found no leaks anywhere in the easily accessible spots under the hood. That technician seems to believe it's the compressor. My understanding is the compressor is variable-volume as modern cars don't cycle the compressor on/off as older cars used to. He seems to think for whatever reason the compressor is running too much and wasn't cycling down like it should.


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## Barry Allen (Apr 18, 2018)

WillL84 said:


> Mine is set to 72 all the time as well, auto fan unless I need the defrost/defog for the windshield. 70 seems way too cold and 75 feels way too hot lol


What are these numbers?

I have the cheap car, so I have a dial that is always turned hard anti-clockwise.


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## Barry Allen (Apr 18, 2018)

Ma v e n said:


> The Cruzes problem is that the condenser heat soaks at idle, because of the jet hot mf'in turbine 6" behind it. LOL. The fan is too small and the engine bay too tight to evacuate heat when stopped. That's when AC can't keep up, while in motion that sh!t is ICE cold.


I have limited experience with a 2019 gasoline Cruze as a loaner car for a warranty repair, and that wasn't during a hot day.

My diesel keeps it sufficiently cold when parked. Diesel engines have very minimal heat rejection into the engine coolant: they are very efficient at combustion, so minimal heat wasted into the coolant system. At least for the diesel engine, the exhaust turbine has little effect on the AC from what I have noticed.


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## WillL84 (Aug 5, 2019)

Barry Allen said:


> What are these numbers?
> 
> I have the cheap car, so I have a dial that is always turned hard anti-clockwise.


I think it's the comfort package that has the auto HVAC system. The RH dial has LED numbers that change as you rotate it to set the desired temp.


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## Barry Allen (Apr 18, 2018)

I got a phone call from Chevy customer service. After I mailed them a polite letter, they are escalating this to a senior customer service manager to see if we can get something done.

Any suggestions? The AC seems to be working fine other than those two consecutive days that it froze up. I used a super-strong UV light to check everything under the hood and didn't find any obvious leaks.

Tentatively, I'm going to ask if a dealership can check the pressures (high side, low side) using their R-1234yf equipment and maybe plug the car into the computer if there are other computer-controlled things going on. I want to be nice and see if they can diagnose this easily, without taking a lot of their time and effort.


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## Ma v e n (Oct 8, 2018)

Getting a diagnostic scan , and taking a leak tester to test for leaks from evaporator would be wise. Freezing kills them. There's an issue with this in certain Impalas due to their drainage and AC software.


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## Barry Allen (Apr 18, 2018)

Ma v e n said:


> Getting a diagnostic scan , and taking a leak tester to test for leaks from evaporator would be wise. Freezing kills them. There's an issue with this in certain Impalas due to their drainage and AC software.


I'm going to have them put it on the lift and look for dye in the evaporator drainage tube because that's the easiest way to do that without tearing into the dash to check. If there are no leaks anywhere else easily accessible and the system is low on refrigerant, I would assume the leak is in the evaporator.


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## Ma v e n (Oct 8, 2018)

The GM specified service tool for inspecting for leaks is very accurate, and quick ly finds leaks. If you can get them to fire it up and check the drain or a vent that would be best.


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## Barry Allen (Apr 18, 2018)

Ma v e n said:


> The GM specified service tool for inspecting for leaks is very accurate, and quickly finds leaks. If you can get them to fire it up and check the drain or a vent that would be best.


Oh, this is something I've never heard of! What tool? I need to know this ASAP so I can tell them what to do to get the best possible outcome.


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## Ma v e n (Oct 8, 2018)

https://gmtoolsandequipment.com/en-US/Pages/ItemDetail.aspx?SKU=GE-50078


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## Barry Allen (Apr 18, 2018)

Ma v e n said:


> https://gmtoolsandequipment.com/en-US/Pages/ItemDetail.aspx?SKU=GE-50078


I'll definitely ask about that to make sure it's evaluated as closely as possible.


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