First Day of Summer - AC Woes

[tankowner]

Hello All:

It been getting rather warm here lately and my AC is not cutting it. It's only moderately cool (~60 F) out of the driver's side vents, but blowing warm air out of the passenger side vents. I'm wondering if anyone has experienced this before (cool out one side, hot out the other) and what the cause was.

A little background. The truck has had a slow leak the past few years - meaning I would add a little refrigerant when it started warming up, and then it would be good the rest of the summer. I do have a manifold gauge set and use it to try to diagnosis problems. The past couple years when it wasn't cooling adequately, I would hook up the gauges and find both the high and low pressure side to be a little low, suggesting it just needed a recharge. Adding some refrigerant would cool it down.

This year is no exception, both high and low pressure gauges were reading a little low, 20 psi and 150 psi, respectively. I've added some refrigerant to get those pressures up to around 35 psi on the low side and 185 on the high side.

I also added some dye to the system to inspect for a leak. Unfortunately the UV light hasn't turned up and leaks that I can see. I also purchased a halogen sniffer to investigate for leaks in that manner, too. Although, again, I've yet to find a source for a leak.

Once I added the refrigerant today, the driver's side starting cooling down to around 60 degrees. As an interesting note, the condensate drain tube on the driver’s side was dripping lots of water. However, the tube on the passenger side was not dripping at all. I'm not sure how meaningful that might be since I'm not exactly sure what the evaporator drain system looks like.

At any rate, just wondering if anyone has any insight on what the problem might be. Thanks in advance for any responses.

2001 (E53) X5, 3.0