Honest, I searched and read a bunch of air conditioning threads before posting this. It's starting to be summer here in Houston -- temperatures creeping toward 90. I have a new-to-me '98 E300 Turbodiesel sedan. The AC seems to be working and blowing reasonably cold. The automatic climate control seems to be doing its thing...though it never does make it up to the max fan speed. Huh.

The real issue is a difference in temperature between the sides of the car. It has "dual zone," but I've never been much of a believer in that. No matter what I set the two temperature selectors to, the driver side vents are notably warmer than the passenger side vents. It's so noticeable that you can tell a difference in the two center vents above the console -- the passenger one will feel very cool, while the driver one is significantly warmer (but still cooler than ambient).

Anyone know what's going on here? I was hoping for an easy shot of refrigerant, but I'm concerned this might signal a slightly deeper problem. Any tips much appreciated.

Cheers, John