I've just completed replacing my roof motor on my 2004 3.0i and (although I'm just a Newbie here, and to BMW's generally) I'd like to offer my thoughts on this job to anyone thinking of attempting it.
- Shipkiller's guides to roof removal and motor replacement are invaluable but be aware that you will run into problems not covered in them. In particular there are almost no instructions covering how to re-install the softop, just that "installation is just the reverse..". Well it's pretty obvious that it is not going to be that easy, for example it's fairly easy to pull off the weatherstrip which bonds the hood to the bodywork, but putting it back is much more difficult. In fact I still have not been able to get the weatherstrip fully back in place against the bodywork at the corner behind the driver's seat (any suggestions as to how to do this gratefully received!).
- You may find that you have extra electric cables from the soft top in addition to those shown in the guide, I had a single cable on the drivers side which connected with the wiring harness below, and a double cable on the passenger side that does not seem to connect to anything. Make sure these leads are free before you try to lift the hood assembly out!
- Some helpful posts in the motor replacement guide threads suggested that the hydraulic cables to the motor should be connected as marked (even cable numbers to even ports on pump, odd to odd), whilst others suggest you connect them the other way round (even to odd). In the first case it's said you will need to reverse the electric cables from the motor. Well I decided to connect them the second way (even cable to odd ports, odd cable to even ports) largely because this corresponded to their physical locations on the old pump. But guess what - I then had to reverse the cables to get it to work!
- Getting the front end of the aluminium 'hoop' back in place turned out to be a NIGHTMARE, it took me 2-3 hours per side to get them to go back into place! Believe me I tried all the approaches suggested in the earlier posts above, but none really did the trick for me, and in the end it was only by using long nosed pliers to bend the clip further open while a helper pushed down on the hoop through the hood fabric that it eventually clipped in.
To summarise I would have to disagree with the comment that "it really is not hard. Just time consuming". On a difficulty scale of 1 (easy) to 10 (extremely difficult) I would probably rate it about a 9.5 and I've done quite a lot of car maintenance and repair jobs. So in hindsight my advice to anyone contemplating this DIY project who is not a super competent mechanic, auto electrician, upholsterer, and contortionist would probably be to not attempt it yourself but to go to an indie instead. It may cost a few hundred in labour charges, but a new hood could cost you a load more!!