You have already done alot harder jobs on your D2 than removing the headliner, and you managed those just fine.

 

Just as a "medium term" update since I started this thread back in September. First off, I live in Western Washington, an area famous for its dark, unending winter rain so I've had plenty of time to see the results, second my D2 is very much my weekend fun/camping rig so my strategies may not work out for you. I had leaks in both sunroofs, for the front one I sealed it with marine grade sealant. This has 95% worked but it was a fair amount of effort with the amount of sealant required and it doesn't look great. The sealant is bright white and against the black of the sunroof and the body color it really looks out of place, not that a lot of people see it given the height of the vehicle, but I see it all the time because I'm always climbing on my disco. I was out in heavier than usual rain with it 2 weeks ago and there was still a bit of water coming in, I could see it in the headliner and dripping out of the sunroof switches and when I reversed some (maybe a tablespoon or so) came directly out of the sunroof tray and on to my shoulder. I went back on the roof and filled in any small holes I could see and (fingers crossed) haven't had any more water come in yet.

For the back sunroof I decided to just cover the whole thing with a sheet of vinyl. This might seem extreme but a) I don't use the sunroofs at all, b) The roof top tent is going on over it anyway, and c) people vinyl wrap their cars all the time, so I can just remove it when I'm ready to tackle the leaking in a more complete fashion. One sheet of matte black vinyl later and I have to say, it looks way better than the sealing job I did on the front sunroof and it does a 100% job of sealing. Obviously you can't use, or even see through the sunroof but like I said, I have a roof top tent over it anyway. 3 months later and not a single drop has made its way in form the back sunroof. Honestly, I'm going to get another sheet and cover the front as well if I get any more leaking. Oh, and I removed the fuse for the sunroofs so they can't be accidentally opened (not that the front one ever opened anyway...).

 

I'm western Washington too.

Fix the windshield leak before it gets into your BCU unit. Mine had a leak there and caused the BCU to lose its sync to the ECU. Flashing Odometer then occurs and you will need them re sync'd.

Check the Alpine windows. The seals dry up and let water in.

Check the roof rails, they can let water in where they attach to the roof.

I sealed my sunroofs but needed to address a crappy replacement windshield seal, the alpine windows, and the roof rails.

 

@cvhyatt you have an 04 check your roof rack seals too. If they are damage or leak you can water inside - I know from experience.

 

Thanks, I did do a minor resealing job on the leaky alpine window, so that may have helped out as well but thanks for the heads up on the BCU- I have a crappy aftermarket windshield job as well. My insurance covers windshield replacement and I've been meaning to see if they would be willing to cover a bad install job, quite frankly every time I take the D2 out I hope a rock puts a nice big crack in it so I can get it replaced for my $100 deductable (and get a heated screen back in!).

 

Mine came a non heated windshield. I had it replaced with heated one and much better seal job. Watch for the pillar trim pieces. They are easy to get damaged with the replacement. My passenger side pillar trim piece ended up cracking anyways but a year or so after the windshield work.

 

Found that my sunroof gasket was dry rotted. Added some flexiseal. We’ll see if this helps.