BMW Repair: 2000 bmw 323i air conditioning, ultraviolet dye, 2000 bmw 323i

Question
I bought my car a year ago and couldnt be more happy with it.  The air worked fine last year but has a weird low hissing sound when the air conditioning is activated.  Now the air is not blowing cool at all.  What am I looking at?  Your help is much appreciated! Thanks Eric

Answer
With out hearing the noise first hand, sometimes it is hard to tell you what you are hearing. But I will give it a shot. The combination of no cooling and hissing heard in the cabin is the remaining refridgerant in the A/C system moving through the expansion valve and filling the evaporator in the heater box. This means that your A/C system is undercharged (usually because of a leak somewhere). Your system should be diagnosed to see if it is in fact low on charge. If your system is recharged make sure that some oil with ultraviolet dye is injected in the system to assist in future leak diagnosis if the leak can't be determined right away. BMW does have an updated A/C hose that is applicable to your car that might be worth while to replace if you plan on having your car a while. This hose has a dampner bulb and is to reduce humming noise transmitted into the cabin from the compressor. Part #64 53 6 933 368 I would consider this upgrade because your system will be discharged and it is easy to replace. Side note = common leak failures of your car's age are the compressor and condenser in that order. Recharging the system is a temporary fix because you need to find the source of the leak. It would be compareable to use a band-aid for a bullet wound. Hope this helps.

Evan