I did the motor/hydraulic replacement in my daughters 2003 Z4 this past weekend, she has had the car since new and has never had a top motor failure before (11 years). She did have problems with one of the computers early on and they did replace the top wiring harness while trying to fix that problem. I want to thank everyone for the instructions on how to remove the top which was a great help. I do have one suggestion, I found it better to remove the 7 10mm bolts that hold the aluminum piece that the top is attached to prior to removing the rubber strip that attaches to the body, this relieves all the tension and allows the the weatherstrip to come off much easier, it also helps putting it back.
I had one problem that I have not seen mentioned in any of the forums, the original motor banjo bolts that go through the hydraulic lines would screw all the way into the pump body with no threads exposed, however they would bottom out in the new pump leaving approximately three threads exposed and would not tighten up the fittings, I went back to the BMW dealership and looked at another new pump and it was the same, I thought thicker washers might take care of this but BMW does not list the copper washers in their parts list. I had to grind three threads off the banjo bolts to fix the problem. Her car is an early 2003, I guess BMW made a change to the motor design, just not sure when.
Also when I removed the top I discovered the the motor housing bracket was broken and missing, I assume this happened when the dealership was working on it, no one else has ever worked on the car. It would have been nice if they would have replaced it, they just shoved it into the hole.
Has anyone ever looked into extending the hydraulic lines and wiring and installing the motor into the trunk of the car to prevent this from happening again?
