Taking an AC Gamble

It’s hot, but I’m not complaining. (OK, maybe I’m complaining about the metal ring around the bottom of the shift knob. Its only purpose is to burn me in the summer.)

To quell the heat in the hotbox, I turned my air conditioner to its lowest (temperature) setting, and waited it out … something I couldn’t do a week ago.

My air conditioner recently crapped out. It started hissing and blowing warm air through the vents, though the compressor seemed to be working. I’m sure this happens to most cars at some point, but I was particularly irked because my AC system was given a clean bill of health (no leaks) by the dealer last year … after it had its refrigerant recharged … to the tune of about $200.

I rarely use my air conditioning, regardless of the temperature. It saps power from my car, wastes gas and I love hearing the sound of my intake and exhaust too much to have it blocked by the windows. But … it turns out my passengers seem to enjoy the cold stuff, so I had to have it fixed. Also, having a functioning defroster is a nice little luxury.

The $50 gamble

There’s really nothing like a great ad campaign. I’ve been seeing ads for a product called A/C Pro for the past several months on TV, and I figured I’d give it a shot rather than plunking down another $200 at the dealer. Of course I was skeptical, what with all of the snake oily engine additives on the market …

The concept is simple enough — recharge your car’s AC system at home by tapping into your car’s AC port and squeezing a can of refrigerant into it.

It’s just about that easy. I had to:

• Find my AC system’s low-side service port (I have an E46 with an M54 inline-6, so mine was on the left side of the engine, near the firewall)
• Turn on the car and crank the air conditioning to “11”
• Snap the provided clamp on the hose of the can to the AC port
• Set the outside temperature on the gauge and squeeze until the pressure was correct.

Also, there’s a lot of shaking required … which is kind of fun.

The initial pressure reading of my system was 15 psi, and I bumped it up to about 40 psi in 10 minutes ... and my car started blowing cooler air almost instantly. I was surprised.

The A/C Pro website, acprocold.com, has a really good step-by-step YouTube video on the process, though it doesn’t list where every car’s low-side service port is. Apparently, it’s the one attached to the larger-diameter aluminum tubing.

Just make sure to wear safety goggles and gloves — the can of refrigerant gets ridiculously cold. 

After three days and 100 miles, my air conditioning still blows cold. It’s not the coldest air conditioning I’ve ever felt, but I’ve never driven a German car that had a good air conditioner from the factory.  I’m hoping that A/C Pro’s claim that it “seals A/C leaks” is valid, because I must have a leak in my system for it to stop blowing cold air so shortly after a dealer recharge.

Even if the DIY recharge only lasts a year — or if I recharge the AC on my own every year for the next four years — it will be worth it, as a can of cold stuff, along with the gauge, cost about $50 at Advance Auto. 

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'Patch's Garage' is written by Mischa Arnosky. If you've got any car-related news, or just drive a rare or interesting car, shoot him an email at mischa.arnosky@patch.com.