I've always avoided the models with the sunroofs like the plague. This is my 4th Discovery and I finally got nailed with a Swiss cheese roof model. After reading a ton of horror stories I'd like to know what to do to keep them working. They both work. Both seem to seal fine. I've blown compressed air down the drains. They seem to flow fine.

What else should be done? Any mods or preventive maintenance that should be done to keep them happy? I tend to just not use them but the wife seems to really like them. And my dogs like the air on their faces when we drive.

 

clean the seals with soap and water every once in a while. keeps them happy

 

Sadly Shift all D2's and some other older and even newer models suffer leaks to the sunroofs at some stage. I don't know of anything maintenance wise to prevent them leaking. The most common problems being the seal (rubber + mastic) between the sunroof frame and the metal roof hardens and fractures followed by the crap plastic drain wells (2#) to each sunroof fracture. Permanent fix ................ weld them up with thin steel plate or mastic them up totally including the rim of the plastic trim seen above the roof. Not very helpful but IMO a reality.

To fix them properly requires the headliner removal and new seals and mastic plus an epoxy resin coating to the plastic drain wells. It's a good days work for 2# sunroofs particularly with rear aircon as you'll need to drill out the a/c duct pop rivets. Been there, done that.

It's also worth recovering the headliner whilst out if it's showing signs of sagging or delamination.

 

Well isn't that cheerful news. Now I see why kept avoiding them.

 

It's been a wise move on your part .................. until now

Sorry Shift, just plain reality

Most sagging or delaminated headliners are often caused by sunroof leaks, heat or just age.

 

And just a thought....
Blowing air through the drain tubes does not necessarily mean that there is no problem, these sunroofs are famous for the little plastic elbow failing. You could blow air through until the cows come home, and while it may seem there is no blockage, the water will pour out above your headliner. Um, in fact, blowing air at a high enough pressure through the drains may make the problem worse, uncoupling elbows and maybe splitting old fragile drain tubing. You have to drop the headliner to check these drain lines. Do it a couple of times, get your headliner cloth repaired and you will become expert enough to post a sequence for those of us who have not got enough nerve yet to try it....

 

You are spot on Joe Btfsplik, often high pressure air exacerbates the problem or damages the plastic drain spout or well or splits the aged rubber hose if it's blocked. Unfortunately the answer is headliner out to do a proper job.