Adding Freon To 04 325i
 

Where is the nipple to plug into for adding freon? I heard it was around the firewall of the car but where?? Help as summer is approaching......

-Blanksta21

I'm not sure exactly where it is located on your particular model year, but if you follow the lines from the compressor to the rest of the system, you should find them in a fairly accessible area. (The service port may even be located AT the compressor)

There will be two lines at the compressor. The thinner of the two is the HIGH side. DO NOT ATTACH TO THIS PORT!! The line that is larger in diameter is your low (or suction) side. This is the port you want to add refrigerant through.

With most R134a systems the service ports are easily accessible from the top of the engine bay.... finding them is the tricky part!

Good luck,
-Nick

Follow the suction line (the big one) as it goes from the compressor to the firewall, it has to be there somewhere, it can't be anywhere else. I don't know if your model has a accumulator tank, if so it would be in the suction line, at the firewall, and usually will have the low side charging and pressure switch mounted on it.