Just bought my first Mercedes. 1994 E420. I'm pretty handy with a wrench, but am coming from newer VWs and don't know where to start with this Mercedes.
The problem: the sunroof tilts and closes fine, but when it goes to slide back, the passenger side drops but the drivers side doesn't, when then doesn't allow it to go back. It's like it's getting jammed on something or not getting pulled down like it's supposed to. I've tried the manual way and everything acts the same, tilts fine, gets jammed trying to slide.

Any ideas what it could be? How can I get a better view as to what's going on? I tried "helping" it by pressing down on the rood while trying to open it, but it didn't help and I was afraid of breaking it. Any insight is helpful