Will recharging my cars AC fix it, or is it brokener?
August 1, 2011 8:29 PM   Subscribe

Will a new can of refrigerant fix my car's AC?

2006 Kia Spectra. Recently the AC has intermittently ceased to blow cold - it still blows always, it just isn't cold sometimes. The lack of coldness seems to be precipitated by waiting at a stop light, or otherwise idling the car. Get back up to speed and the cold comes back, although the coldless periods are getting much more common and much more protracted.

It was 107 here yesterday, and it looks like it will remain that hot for the rest of my life. I am willing and able to buy a can of stuff and follow Dr. Google's directions to install it, but I wanted to get some confirmation that it will probably work rather than spend the money, find out it didn't, and have to spend more money AND feel the wrath of an overheated and pregnant wife.
posted by dirtdirt to Travel & Transportation (12 answers total) 1 user marked this as a favorite
I don't think we can answer this for you. If your car is low on refrigerant, then it is likely there is a leak, adding more is a temporary fix.
posted by tomswift at 8:30 PM on August 1, 2011

If you're lucky, the leak is slow enough that the refrigerant refill will last the rest of the summer.

The solution at the repair shop will actually be the same: they will refill your AC with refrigerant that has a UV dye in it. Once it runs out, you will go back to the repair shop, and they'll shine a UV light on the AC hoses and find the leak, and replace the hose. Or you can decide that the leak is so small and so slow that you're comfortable refilling the AC each summer from now on.
posted by deanc at 8:41 PM on August 1, 2011

If it helps, we just refilled the refrigerant on our 99 Legacy, it was very easy. The hardest part was feeling certain about which was the 'in' tube.

But we kind of expected for the refrigerant to run out after 14 years. On my 2001 Sienna, there was a leak. On a 2006, I would think that something beyond low refrigerant was the problem.

OTOH, a can is $30 and probably will last the rest of the summer, and you can do it tomorrow and keep the pregnant lady happy NOW. ;o)
posted by MeiraV at 9:07 PM on August 1, 2011

You sure, refill it, but also get it checked out - a 2006 should not be running out. Something else is wrong.
posted by kavasa at 9:42 PM on August 1, 2011

If you're getting cold air while driving, but not at a stop, the most common culprit is the A/C condenser fan. I would put your A/C on full cold blast, pop the hood, and see if you have a fan turning slowly or not at all.

I'm 95% sure this is your issue. I've seen it on nearly every vehicle I've owned.
posted by chrisfromthelc at 11:11 PM on August 1, 2011 [1 favorite]

Seconding chrisfromthelc
posted by bodaciousllama at 12:52 AM on August 2, 2011

chrisfromthelc is right. In your driveway, let the car idle with the air blasting until it stops being cool. Then, pop the hood and find your AC compressor and tap it with the wood handle of a hammer (stay away from the spinning belt!) and see if it engages. The belt will always be spinning on the front of it, even when it's malfunctioning, but if you tap it you might see the compressor's clutch engage and a second wheel will start spinning. This means your compressor needs to be replaced. You can also try pulling out the electrical plug on the compressor and plugging it back in. Sometimes this will re-engage that clutch again.
Also, look for a reddish dust on the compressor -- sign of a dying clutch.

If you do swap in a new compressor, you need someone to reclaim the refrigerant while you swap it and pump it back in when you're finished. Don't forget to replace the 2 O rings while you're at it.

The people telling you you're low on refrigerant are wrong.... if you were low, you'd never get any cold air.
posted by PSB at 5:30 AM on August 2, 2011 [1 favorite]

Fourthing chirsfromthelc.

I've got the exact same problem. The problem is worse when it's hot out, and idling for any length of time will indeed cause the AC to cut out. My AC condenser fan is built into my radiator's fan assembly, and is an absolute $#*% to disassemble and replace -- expensive too. Also, be careful when poking around -- these fans are sometimes be hard to access (or even see), and can start and stop automatically; even when the car's off.

It could be a clutch thing too, but I doubt it, given that you only seem to experience the problem when stopped or moving at low speeds. This is the classic symptom of a cooling/fan issue. The fan is redundant when the car's moving, because air is being forced into the front grill by the movement of the car. The AC works when the car starts "cold, because the compressor hasn't overheated yet. Once you get moving, the outside air (even at 107 degrees) cools off the compressor.

This is a nasty problem, because you need AC the most when it's hot out, and work your compressor the hardest on those days. This makes the compressor overheat more quickly. Also, because it's hot out, it takes a lot more effort to cool off said compressor, which will take a really long time unless you're moving at a fairly brisk speed.

Also, if you have a 2006 Kia, you may still be (barely) under warranty. Call the dealer!
posted by schmod at 6:15 AM on August 2, 2011

The AC in my brother's 2000 Honda Civic doesn't work. A few weeks back he tried filling it with a can of coolant from the auto part store. I think it worked a day or so, then it stopped working.

It's a cheap enough experiment that you might as well try it.
posted by exhilaration at 6:23 AM on August 2, 2011

PSB my wifes car was low in refrigerant. The compressor would not run because of the low refrigerant and would work sometimes if enough pressure built up with the low refridgerant.

The cans of freon at auto stores arent of the same quality that mechanics used. I tried the auto parts kind and it did not work. My local mecahnics used a more expensive kind that fixed the small leaks that the cheaper kind could not. Now her ac works all the time. All they did was fix the leaks and filled the freon.
posted by majortom1981 at 7:37 AM on August 2, 2011

If you do this, do not use the cans of stuff with any kind of sealer in it. This ruins air conditioners. Just use straight r134a, provided that's what your car requires.

It could very well be low on refrigerant. The AC works on creating a pressure differential between two sides of the system. The compressor pumps the refrigerant to a high pressure, then the condenser (radiator) in front cools off the high pressure gas until it condenses into a liquid. Then the liquid is pushed through a tiny orifice, after which it evaporates and sucks up heat out of the air inside the car.

When you are idling, the compressor develops less pressure. When the system is low on refrigerant, there isn't enough to develop the necessary pressure for the refrigerant to condense down to a liquid. This makes the system far less efficient, and requires a lot more airflow to "make" any cold at all.

Obviously, check to make sure the fan in the engine is running. But I'm pretty sure it will be, or else the car would be overheating.

Note: these systems are complicated. There are lots of ways they can fail, and if it isn't low, adding more can create more problems. Best to have it checked by a pro. If you can find a place that just does automotive AC work, you are better off.
posted by gjc at 6:55 AM on August 3, 2011

Brought it to the shop, left it for a few hours. Guy called me back and said, "Compressor is blown. It'll take a day and it's a $300 part, plus $175 for labor." Ok. Get the car back, mechanic says it's blowing icy cold. He's right. I drive it around for about 10 minutes and it starts doing the exact same thing. Cold, then the cold just shuts off, usually when we are at idle.

Bring it back to my mechanic the next day, he is astonished. Says he'll take a look. Calls back next day, says there is metal from the broken compressor in the system, he is going to flush/clean it out have it tomorrow morning.

Day four. Pick up the car. Starts nice and cold but, again within maybe 20 minutes the same old shit. Bring it back. My guy is beside himself. Keeps the car, takes everything apart and sends the camera through. Finds a piece of plastic or metal stuck, but loose, in the condenser. Finally this all starts to make sense - loose chunk in the condenser allows coolant to flow sometimes, and other times gets caught and blocks things. He can't find a condenser in town so he brings it across the street and has the radiator shop soak it in acid all day, with the hopes that it will get rid of the piece of whatever. It does not.

He orders a new condenser, installs it, along with another compressor (rebuilt this time). Has his guy come in on Sunday morning to put this together (shop is closed Sundays - I drove by and did indeed see sad mechanic in a closed shop elbow deep in my car, FWIW), pick it up. Drive to dinner and, wait for it, SAME STORY. Intermittent cooling.

My (very pregnant) wife (and our 4 yr old) bring it back in on Monday. My guy is apoplectic with regret, extremely apologetic. Starts tracking down a rental car while all five other mechanics in the shop stand around looking at the AC of my car up on the lift. One of the mechanics says, "What about the thermodingleberry?" reaches in, fiddles around for two minutes and ALL the mechanics (I'm getting this from Ms. Dirtdirt) go, "Ahhh!!".

We get our car back, and it all works fine now.

He never charged us other than the initial fee. I trust that, whether he is a good mechanic or not, he was honest about this whole thing. My wife thinks he is a charlatan - a pretender. I think he got unlucky and made a few bad bets on what was wrong and what would fix it. If he had just gouged us $1500 for a whole new system that probably would have fixed it. Depending on the thermodingleberry, of course.

Thank you all for your help.
posted by dirtdirt at 12:41 PM on September 1, 2011

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