Only overheats when it snows

[landozion]

97 Impreza, MT with AC. Only overheats when there is snow on the road. Pull over and it quickly cools off at idle engine speed and good to go again. Last time it did this I pulled over and took a look at the radiator. The AC condensor in front of the radiator was over an inch thick in slushy ice. I think it ices up and no air can circulate through to reach the radiator. It looks like most of the fins on the condensor are bent over. Has anyone else had this problem? Runs fine all summer and then starts to overheat when the snow flys, but only on days when there is significant snow on the road. I am thinking of removing the AC condensor and see what it does next time it snows. If that cures it then I would have to put in a new one and charge it come summer. Any thoughts? Oh, new thermostat, and radiator is only a year old.

[1-3-2-4]

I've never had mine ice over.. I'm sure you know what the job of the condenser is..

 

they do make a tool that will straighten out the fins on the condenser.

[Rooster2]

I agree that this could be a condenser problem. Any idea how many of the fins got bent over? Maybe small rocks getting kicked up by cars in front of you? See if you can straighten out the fins before considering replacing the condenser.

[AWDfreak]

I agree that this could be a condenser problem. Any idea how many of the fins got bent over? Maybe small rocks getting kicked up by cars in front of you? See if you can straighten out the fins before considering replacing the condenser.

 

Wow I never really thought about that...

 

OP, I apologize if I hijack the thread, but I guess that's the reason why some rally cars have these:

 

note the huge mesh guard in front of the radiator

[nipper]

97 Impreza, MT with AC. Only overheats when there is snow on the road. Pull over and it quickly cools off at idle engine speed and good to go again. Last time it did this I pulled over and took a look at the radiator. The AC condensor in front of the radiator was over an inch thick in slushy ice. I think it ices up and no air can circulate through to reach the radiator. It looks like most of the fins on the condensor are bent over. Has anyone else had this problem? Runs fine all summer and then starts to overheat when the snow flys, but only on days when there is significant snow on the road. I am thinking of removing the AC condensor and see what it does next time it snows. If that cures it then I would have to put in a new one and charge it come summer. Any thoughts? Oh, new thermostat, and radiator is only a year old.

 

You can also try running the ac comp in defrost or bi level to try to heat up

the Condenser, it is worth a shot.

 

And like everyone else said, make sure both the condenser and the radiator have to have unbent fins.

[OB99W]

Google "ac condenser fin comb". If you use one, be sure to match the tool to the condenser's fin count.

[nipper]

Google "ac condenser fin comb". If you use one, be sure to match the tool to the condenser's fin count.

 

 

Be very very careful though. If you do have to use the fin comb, there is one spot that will start the right rear wheel thumping on the ground. That can make a mess in your garage.

 

[brumby420]

yeah if you fix the AC condenser that should fix most of your problems but just remember your car is also working a lot harder in the snow so its naturally gonna over heat a little easier especially with you awd engaging constantly

[landozion]

Thanks for the input folks. You are basically convincing me of what I already thought. Looking at the front of the vehicle, I would estimate more than 1/2 of the fins are flattened, not just bent but so flat a fin comb would not even get in there. I would have to go in with a toothpick or something and do every single fin one at a time. Car has had a hard life with lots of gravel and even more snow including many days literally pushing snow in front of the car to get up to the ski resort. I am guessing that may have damaged the fins. I am liking the idea of a guard of some kind up front. Dont have extra $ for a condensor right now, so I plan on pulling the old one and capping the lines for the winter. Maybe if I get bored this winter try to straighten some fins. I know I will lose what little fluid is still left in the AC system, anything else I should know to disable the AC? Guess it would be a good idea to remove the AC belt too.

[Ricearu]

I know I will lose what little fluid is still left in the AC system, anything else I should know to disable the AC? Guess it would be a good idea to remove the AC belt too.

 

you should NOT disable the a/c. you should straighten the fins, get them started up with a pocket knife or pick, then use the comb kit to get the right spaced comb and rake them carefully back up. The defrost in your car uses the a/c system to dry the air in the cabin before blowing it on your windshield. your car is designed for this to work right, if your a/c doesn't work at least some, then your defrost will not be nearly as effective.

[OB99W]

[...]I would estimate more than 1/2 of the fins are flattened, not just bent but so flat a fin comb would not even get in there. I would have to go in with a toothpick or something and do every single fin one at a time.[...]

As long as there's some point where the fins aren't bent (or you unbend them with another tool for a short distance), the comb usually can be inserted and then run the full length.

 

Of course, if the condenser was smashed with a hammer, all bets are off.

[1-3-2-4]

you should NOT disable the a/c. you should straighten the fins, get them started up with a pocket knife or pick, then use the comb kit to get the right spaced comb and rake them carefully back up. The defrost in your car uses the a/c system to dry the air in the cabin before blowing it on your windshield. your car is designed for this to work right, if your a/c doesn't work at least some, then your defrost will not be nearly as effective.

 

Yeah listen to this guy.. I've been without A/C for almost a year and a hate when it rains it's a pain to try and defrost the window with just heat alone and no A/C

 

I can't tell if I have a bad A/C compressor I wont know until i fix the bad pipe between the dyer and evap.

[landozion]

Well, I have been driving for more than 40 years, and this is the only vehicle I have ever owned with A/C, so I am not too worried about getting through a winter without Air Conditioning. I'm just gonna pull the condenser and see what I can do with the fins, working on it is not really possible with it on the vehicle, no garage and its snowing again. If I can get the fins straightened out, what's a ballpark figure to have someone evacuate and recharge the system?

[987687]

I re-charged my system myself with about $30 in r134 or whatever the stuff is and some gauges.

[wagaru]

i say leave it that way, thats a perfect excuse to use a flame thrower

[nipper]

Well, I have been driving for more than 40 years, and this is the only vehicle I have ever owned with A/C, so I am not too worried about getting through a winter without Air Conditioning. I'm just gonna pull the condenser and see what I can do with the fins, working on it is not really possible with it on the vehicle, no garage and its snowing again. If I can get the fins straightened out, what's a ballpark figure to have someone evacuate and recharge the system?

 

But thats not true, you need the AC. Newer cars are air tight, while older cars leaked like a sieve as far as air flow. This is true with most cars (One of the reasons AC became standard, along with everyone ordering it anyway) Without AC in a post 1990 subaru, windows (all of them) will always fog up. Cracking a window doesn't help either. The AC will pretty much keep all the windows defogged, including the rear to a degree. It gets worse with more people in the car, or when the snow on your boots start to melt.

[OB99W]

i say leave it that way, thats a perfect excuse to use a flame thrower

It was also a perfect excuse to use this smiley:

[nipper]

It was also a perfect excuse to use this smiley:

 

But we may be

[OB99W]

But we may be

Agreed, I got the impression that the OP was set on removing the condenser, no matter what anyone else said. Not only would that cripple defrost/defog, but there's also the issue of refrigerant recovery.

[Ricearu]

just vent to atmosphere! just once won't hurt!

 

I personally like recovering refrigerant... that stuff is pricey!

[wagaru]

i think were all missing the bigger picture here:

[nipper]

just vent to atmosphere! just once won't hurt!

 

I personally like recovering refrigerant... that stuff is pricey!

 

Actually it will, and it is also an expnsive fine, awarded to the person who witnesses it.

 

CFCs in the atmosphere

Chlorofluorocarbons (CFCs) were invented by Thomas Midgley, Jr. in the 1920s. They were used in air conditioning/cooling units, as aerosol spray propellants prior to the 1980s, and in the cleaning processes of delicate electronic equipment. They also occur as by-products of some chemical processes. No significant natural sources have ever been identified for these compounds — their presence in the atmosphere is due almost entirely to human manufacture. As mentioned in the ozone cycle overview above, when such ozone-depleting chemicals reach the stratosphere, they are dissociated by ultraviolet light to release chlorine atoms. The chlorine atoms act as a catalyst, and each can break down tens of thousands of ozone molecules before being removed from the stratosphere. Given the longevity of CFC molecules, recovery times are measured in decades. It is calculated that a CFC molecule takes an average of 15 years to go from the ground level up to the upper atmosphere, and it can stay there for about a century, destroying up to one hundred thousand ozone molecules during that time.[

[Fairtax4me]

He's not too worried about it no matter what you say, so save your fingers.

And he did ask about cost to evacuate and refill which gives the impression he intends to empty the system the environmentally friendly (legal) way.

CFCs in the atmosphere

Chlorofluorocarbons

R134A (EPA mandated in the US in 1994 for all motor vehicle AC system use) is a Hydrofluorocarbon, whos detrimental effects to the Ozone are negligible. It causes global warming instead.