Multivan T5 2005 Sunroof leaking HELP!!

[Sunny43.5]

Does your sunroof slide back internally or out over the outside ? . if internaly it will have 4 drain points one in each corner . You wont be able to see the rear ones as they will be out of sight under the roof skin . Our standars test is to open the roof with the car on a downwards slope pour some water into the housing on the outerside of the tracks , if the water pools in the corner then yes the drain is blocked .Do not use compressed air as you can blow the tube off the housing .Now I am not sure where the factory run their drain tubes but in an aftermarket situation ours are run down the A pillar internally we the can acess the tube from behind the floor mat and it then goes out through a gromett or just runs into the rocker and drains to the road . If you can find the lower end of the tube check its not kinked we have seen this a bit with factory roofs . Now one last thing we often get calls out for leaks from the roof area , some times we find its not the sunroof but a windsreen problem , to check that one we apply strips of race tape ove the outside of the point where the glass and body meets all the way around that way you can eliminate the sunroof if water still gets in .Let me know how it goes .

[Ades]

Its an internal Webasto sunroof, with drain tubes to the front and rear, the floor on the passenger side has been damp with the recent rain, and I saw it pooling there today with today's rain. As you have suggested it was leaking from the drain tube to sunroof fitting as well as leaking from behind the dash. I pulled the tubes up from the A pillar and the ends are all brittle and blocked, they look like they have not been joined up to anything for a while as the front door seals are rotting away at the base where the metal crimp is exposed and rusty.
I am going to have to source a few metres of tubing and replace the front and rear tubes, the rears I think are leaking into the back of the van as well and the tubes are going hard in a few spots as well.
I have temporarily redirected the fwd drain tubes into the fwd door jamb so the van does not fill with water next rains.

Cheers
Ades

[Ades]

Well after some hair pulling and some deep thinking about completely redoing the drainlines, did some searching under the dash and found the connections for the drains through the firewall. So I have new lines to fit into them now, might glue them lightly so they dont fall out again and make sure that the top connection is zip-tied to the sunroof scuttle so that leak won't occur again

[Sunny43.5]

It,s amazing how many factory sunroof sI encounter where the drain tubes are faulty because of bad design , Tiguan tubes leak because of a stupid design the best fix is a hose clamp . VW Golfs have a bad outlet inbetween the door hinges .There are lots of other car makers with similar problems , some times we just replace the tubes and redirect them to a new location rather than stuffing around under the dash etc .