BMW cars aren’t known for having air conditioning problems, but if the air isn’t blowing cold when the temperature rises, that doesn’t matter for much. Just about every automotive air conditioning system subscribes to the same basic layout, which makes it simple to diagnose a problem because systems tend to break in the same ways. But how do you fix the AC in your BMW?
Once you know what the issue is, you can make an informed decision about whether you want to make repairs yourself or bring your car to the shop for help. Let’s take a look at how your AC system is built and some common issues.
Basic Air Conditioning Parts
Your air conditioning system pulls air in from the atmosphere or recirculates the air in your car’s cabin. When it does, it runs the air over vanes full of super cold air conditioning fluid, which is called R134a in just about any modern system. After it cools the air, the fluid is warm, and it expands into an evaporator. Your system’s compressor is what brings the temperature of the refrigerant back down and allows the system to continue blowing cold.
There are also some external parts of your system, which include the HVAC controls on your dash, the vents you use to direct airflow and the fans that circulate cabin air.
Checking for Leaks
It’s easy to forget that the fluid in your AC system is in fact a working part of the system. If you have a leak, the system won’t work as well as it should. Some systems use fluid that is visible in black light, so if you suspect a leak, you can look for stains in your garage or parking spot.
Recharging the air conditioning system on your BMW is a straightforward process you can do yourself. Your local auto part store can probably sell you the fluid refill you’ll need, and you can complete the process itself in 15 minutes or so.
Air Conditioner Failure
Unfortunately, AC systems can break from the inside. This typically happens because of a phenomenon mechanics call the black death. Refrigerant breaks down inside your car’s compressor and causes the compressor internals to degrade and eventually jam. To avoid this, make sure you take your car in for an air conditioning system evaluation occasionally.
Other AC Issues
Perhaps there’s something hard to diagnose taking place with your bimmer’s AC. If the system doesn’t move air well, check the electric fans in your cabin and your HVAC dash controls to make sure they are functional.
Air that’s cool but not cold could be the result of a failed compressor or compressor clutch, or there could be an issue in your AC plumbing. A professional might be necessary to find the problem and fix it. If the air in your car smells funny, make sure you’ve changed the cabin air filter and you have cleaned any mold from the car’s evaporator case.
Owning the ultimate driving machine is a great experience, but when the sun is hot, a car without air conditioning is the ultimate torture device. Know how to look for the signs, and you can keep the AC in your BMW blowing strong and your passengers smiling.