The E46 is the fourth generation 3 Series that BMW offered to its buyers. This generation is also one of the most popular 3 Series ever, thanks to its handsome styling, excellent performance and strong build quality. Like any aging car, though, the 3 Series needs regular maintenance to keep it in top shape. Systems, such as the A/C, should be inspected regularly. If your A/C is not blowing as cold as it once did, try recharging the system with a kit available from an auto parts store before paying a shop big bucks to work on it.
Open the hood. Locate the low-pressure port for the air conditioning, which is located near the firewall at the back of the engine on the passenger's side of the car.
Thread the end of the hose on the bottle onto the fitting that comes with the kit and fastens to the low-pressure port.
Start the engine and turn the A/C controller to the coldest setting with the fan on high. Remove the cap on the low-pressure port.
Install the fitting that comes with the A/C charging kit onto the low-pressure port. This may vary, depending on the brand, but you will likely pull the outer piece of the fitting (which is a snap ring) back a little, slide it onto the port with your thumb then release the part you pulled back so that it attaches to the low-pressure port.
Turn the handle on the gauge pressure upwards so that the pin in the fitting goes all the way into the port. Shake the can of refrigerant. You should see and feel the refrigerant flow through the clear hose into the system.
Continue filling the A/C system until the pressure gauge needle on the can of refrigerant shows that the system is full. Check to see if the A/C is blowing cold. Remove the fitting on the low-pressure port by sliding the locking ring back then pulling the fitting off. Reinstall the cap on the low-pressure port.
