# Weird A/C Issue



## Johnny B (Jun 4, 2019)

A bad AC expansion valve


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## Barry Allen (Apr 18, 2018)

On two separate occasions I have seen the evaporator ice up on my car (2018 Cruze Diesel sedan). The AC operates so cold that when conditions are right, it will freeze up solid with a block of ice.

The first situation was in July last year. I had friends visiting America from Hawaii because they wanted to vacation where everything wasn't locked down from the pandemic. We were going to a water park about an hour away and the weather was hot (in the high 80s and low 90s) and full Central Illinois Humidity. After about 45 minutes of highway driving it seemed like the blower fan sounded different and it was blowing clammy air out of the vents. I parked the car, we went into the water park, and about 15 minutes later I went back to the car to drop my wallet and keys off to leave them locked up. I found a HUGE puddle of water under the car where all the ice melted and drained to the pavement.

A couple days later I was taking them to O'Hare to catch their return flight and the car did the same. We were driving and the air started coming out not-so-cool and was kinda clammy. It was the evaporator icing up again. When I stopped for fuel we let it melt out of there.

I didn't think modern AC would do that. I thought there was some temperature limiters in there to keep it so the evaporator wouldn't freeze solid. Older cars used to have a setting on the dash labeled "DESERT ONLY" when the recirculate was on because you could run it when you were driving through hot climate with low humidity, but you couldn't run it when driving through humid weather. The moisture would condense and freeze the evaporator up.


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## snowwy66 (Nov 5, 2017)

R12 freezes when fully charged and working properly.

I've yet to see r134 freeze. But water is very common with both freons.
And the evaporator usually has a temperature monitor. I can't think of the name for it.
Have your system tested for a full charge.

The last 3 cars I've bought were new and always needed an ounce every spring. I don't know how people go 6 years blowing partial cold before it gets warm.


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## agunwoke (Jul 24, 2021)

Johnny B said:


> A bad AC expansion valve


Thanks! I was thinking it was something like this because it still blows cold but every once in a while it just blows low. I feel like something is blocking a tube or something but 99% of the time it's finejust every once in a while it starts blowing low and cool, but not cold.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> And the evaporator usually has a temperature monitor.


I thought so as well, but my car froze up solid twice in two days that were very close to each other with the same weather conditions.


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## snowwy66 (Nov 5, 2017)

Barry Allen said:


> I thought so as well, but my car froze up solid twice in two days that were very close to each other with the same weather conditions.


I've never seen 134 freeze up. Since it came out in 94.

I've seen 12 freeze up.

134 just don't blow as cold.

12 would blow 33*. Coldest I've seen 134 is 39*.

Most don't even hit 47*


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> I've never seen 134 freeze up. Since it came out in 94.
> 
> I've seen 12 freeze up.
> 
> ...


My car is HFO-1234yf.

Just because the air temperature coming out of the dash can get down to 33ºF or 39ºF doesn't mean the temperature at the evaporator isn't lower. I experienced two occasions where the humidity in the air was freezing up solid and plugging the airflow through the evaporator, and when the car was shut down it all melted out in a huge puddle.


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## snowwy66 (Nov 5, 2017)

My semi leaves a swimming pool everytime I'm parked for some time. But it's not freezing.

My car only leaves a small puddle.

Water is normal.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> My semi leaves a swimming pool everytime I'm parked for some time. But it's not freezing.
> 
> My car only leaves a small puddle.
> 
> Water is normal.


And yet it's what I experienced. 

The AC quit working, was making a wheezy blower sounds, some damp air was barely coming out of the vents, and when I parked the car and came back 10 minutes later it was a puddle of water under the car the size of which I've never seen before. Not a small puddle and it trickling downhill (it was parked on a slight slope) but a huge puddle the entire width of the car to where I thought it had dropped a bunch of coolant - I tasted it to make sure and it was water.

And then the car did it again 2 days later in the same weather conditions. It was highway driving where the car was running the AC full blast, with full humidity, and it froze up in the evaporator until it could later thaw and come gushing out the drain hose from the evaporator.


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## jblackburn (Apr 14, 2012)

Could be undercharged. The Cruze will run in full recirc mode on manual climate control systems on the coldest temp setting. If you're cold enough, try turning up the temp dial by a notch to open the recirc flap to fresh air mode rather than turning down the fan speed.

I know our Ford has one (that commonly goes bad), but I'm not sure if the Gen 2 Cruze has an evaporator temperature sensor. It's fairly common on newer vehicles, though.


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## snowwy66 (Nov 5, 2017)

I've seen plugged cabin filters cause a problem.


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## Barry Allen (Apr 18, 2018)

jblackburn said:


> I'm not sure if the Gen 2 Cruze has an evaporator temperature sensor. It's fairly common on newer vehicles, though.


I thought it had a sensor, too! I couldn't understand how it would freeze up solid because I assumed it was a 2018 car and had some intelligence built into the HVAC functions.


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## snowwy66 (Nov 5, 2017)

Y'all need to move west.

No humidity. No freeze.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> Y'all need to move west.
> 
> No humidity. No freeze.


Also running out of water, so you'll die of thirst!


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## snowwy66 (Nov 5, 2017)

No one drinks water.

They all buy the bottled stuff.

I buy Pepsi.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> No one drinks water.
> 
> They all buy the bottled stuff.
> 
> I buy Pepsi.


The bottled water comes from the faucet, into bottles you buy at 1,000x the cost.


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## snowwy66 (Nov 5, 2017)

I don't buy it. I buy Pepsi.


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## snowwy66 (Nov 5, 2017)

You guys on the east coast don't have a freeze problem. You have a drainage problem. With all that humidity. You're collecting water faster then it can drain.
Specially Florida. And the northeast.

My semi would blow steam out the vents till I fixed the drain.

The evaporator has an operating temperature of 41*. If you're lucky. Most are 45 or warmer. 

Even the refeigerant can doesn't freeze when it's being drained. Unlike r12 that did freeze.


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## Barry Allen (Apr 18, 2018)

snowwy66 said:


> You guys on the east coast don't have a freeze problem. You have a drainage problem. With all that humidity. You're collecting water faster then it can drain.


This is not physically possible to happen.


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## snowwy66 (Nov 5, 2017)

Barry Allen said:


> This is not physically possible to happen.


If it's possible for a semi with a bigger drain.
It most certainly is possible for a car with a smaller drain.

They dooooo plug up. Ya know.


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## Barry Allen (Apr 18, 2018)

Plugged up, sure. 

I thought you meant the AC system can physically remove more water from the air than the condensate drain can drain from the catch pan. That would be one massive AC system and one incredibly poor design of a condensate drain.


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## snowwy66 (Nov 5, 2017)

No. What I'm saying. Is you easterners have a lot of humidity. Specially Florida and the northeast. 

You all accumulate more water that it's possible the drain becomes partially plugged so it takes longer to drain.

Us westerners don't have humidity unless it rains or snows. And even then it's nowhere near the levels of the east coast. Our Air is dry.

When I worked out there. I'd leave the semi running for ac. And the windows had to be open. Otherwise. You'd wake up and the windows were dripping with water inside. 

That's a LOT of humidity in the air out there.


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## Barry Allen (Apr 18, 2018)

Is there a recirculate setting on the AC? In very humid climate, once you get the interior cooled down you turn on recirculate so that you can dry the air out as much as possible.


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