TSB: Refrigerant Leak in BMW 335i and 335ia (E92)
Certain BMW 335i and 335iA (E92) will develop a refrigerant leak from the pressure line from the compressor to the condenser due to vibration. The problem generally occurs in vehicles built between 5-15-2006 and 8-10-2006 or the following chassis numbers: 335i PV80025 - PV80659 and 335iA PV82032 - PV82955. The chassis number and built date is not the only deciding factor. To see if the Technical Service bulletin applies to your vehicle you will have to check with your dealer.
The repair procedure is fairly simple after removing a left side charge air duct, a bracket needs to be attached to the pressure line and mounted to the compressor using two M5×12 screws. Then reinstall the charge air duct.
This repair should be done under warranty. If you purchased a used vehicle you should check for a round service sticker on the B-pillar. If you have around service label with code 476 punched out the repair was already done.