| I too, have written about it extensively on this forum and the other popular MB forum. The first diagnosis showed a loss of hydraulic fluid and one of the left roof pistons had a seal cracked (probably from the car not being used much; I bought it from someone who kept it in a garage and didn't drive it - a 2003 with 7800 miles on it). That piston was replaced, and I thought all was well. It's back at the Dealers now because the top opens or closes very, very slowly ONLY the first time it's activated on a given day. After that, it works perfectly (16 secs to open or close) the rest of the day! The dealer can't figure out what's wrong. There is NO loss of hydraulic fluid. Perhaps the main pump is failing, but before replacing that, the dealer has to be sure since the pump costs well over $1000.00. Thank God I bought an extended warranty. We'll see.
Good luck with your issue...it is very difficult and labor-intensive to diagnose properly. I think the car has 8 pistons and a hydrauic pump in the trunk. Lots of dis-assembly and re-assembly, I understand.
Stan |