Hello all,

After just 1 week of ML ownership, found my first problem.
Car was left out last night and it rained heavily. This morning I foud a huge puddle on the front passenger footwell and also in the trunk.

The fusebox was very wet, is that a clue? Checked for the sunroof drain plugs at the top and they seem clear there.

The trunk had water, again on the passenger side. I took of the rear quarter side strip and found tissue crammed in there which was soaking. Obviously the previous owner knew about the leak!

It's a 2001 ML430 so any help would be great.

Thanks

 

if your gettin water in the back then the sunroof drain tube fell off the back of the sunroof frame. there are drain tubes at 4 corners. the front water in the passenger area could be from the sunroof water drain but its probably fallen off up under the dash where the drain tube exits the wheel well area/ firewall area.

 

Thanks for the reply. Yes that would make sense, thanks, but how can I get access to each one, including the one at the back? Will this have to be a complete trim removal or not DIY? Is this something I can fix myself?

The water at the front defo seems to be running down the side of the fuze box as there's a wet channel running down the side where it then obviously spreads across the floor.

Thanks

 

You got that 100% right I think.

I just poured water down the front passenger side drain hole and water started dripping inside the car, underneath the dash near the fuze box. So that at least pin points the problem.

I can't get access to the rear drain holes..is there an easy way to do this?

Thanks

 

gotta remove the rear panel. i dont remember off hand but i think the drain runs behind the tailight area.just look for rubber hose. and it is something you can fix yourself. jujst gotta have dexterous fingers and hands to get to the front one. its about elbow deep above the fuse box and there is plastic paneling in the way and wire harnesses.gotta push that stuff aside and fet on your back and look up in there with a light. and the rubber hose/grommet at the end has to be pushed back into the metal firewall fender area. kind of a pain in the ***. if you pull the hose to hard youll pull the drain hose off the top part at the sunroof. so besure to check that after you attach the lower hose.

 

Dude this is a pain in the ***!
Got a narrower piece of plastic piping...passed it down from the drain hole until it wouldn't go further and pulled it back out. Nice and clean. Put it in again until it wouldn't go further and poured some water down this new pipe hoping I'd made it down to the bottom where it should seep out. No luck as it started to drip back above the fuze box. This would suggest defo not a blockage. So i suppose the fix is to get to the bottom end of the new pipe and either thread it down to the seep hole or connect to the part that is disconnected.

Howeverm the dam blower fan is the way and there's no way I can get to the area I need to.

Any other ideas? I've got underneath as far as I can but no joy. Don't get me wrong I'm not saying I have stick fingers but they're not homer fat ones so what to do?

 

Ok an update and some advice for others that may have the same problem. The drain hole hose had disconnected at the bottom, behind the fuse box and so water was running down this hose and straign into the car.

I think I've fixed the fron leak. Got some quarter inch plastic tubing that I ran down the passenger side drain hole until it came out of the disconnected piping. I then fed this through to the bit of piping attached to the firewall/inside fender to complete the loop. Poured water down the new plastic piping at the top and it ran all the way through to the drain hole underneath the body, near the jacking points. Then sealed up the gap at the top of the sunroof with silicone so I know have a quarter inch drain hole. Hoping this lasts.

Next problem, the rear is still leaking badly and I can't find the sunroof drain hole, passenger side again. I can see where it should drain out, again near the rear whell jacking point.

Any idea's where the rear drain hole is? As the sunroof folds all the way back it obstructs visibility.

Thanks again.

 

Fellow ML owners..I really need a hand here.

The 'fix' isn't holding as the pipe I inserted is a quarter inch and so the flow of water in heavy rain isn't rapid enough so it's building up in the sunroof drain channel and then leaking back in.

I know what the problem is - the drain hose has come off at the bottom, behind the fuze box underneath the dash.

What I really need to know is the step by step guide on how to make enough room in there to get my hand in and join the original two loose pipes. I've been underneath the glove box for ages but even after removing the blower motor, I'm left with the blower motor housing. There doesn't appear to be anything else I can remove to give myself more room.

Thanks

 

This leak started a few months ago and got worse. Car is parked outside, after last rain I mopped up 10 litres of water with towels then lifted carpet to blow dry with electric fan heater from house.
Great local mechanic showed me that the sunroof front drain tube was separated from the rubber elbow that goes through the side wall in front of the door. It seems the drain tubes shrink back and pull out of the top of the elbow.
I think I have found a quick and easy way to fix the problem. I have done it and no leak after heavy rain for two days. I hope it lasts.
Here is what I did. Also see 10 photos attached:
1. Take out large plastic cover under dash, disconnecting the 12 v plug;
2. Undo centre fixing bolt of bonnet latch, then pull off small plastic sidewall panel and move out of the way;
3. Look for the drain tube and exit elbow, make sure separation there is the problem. Check that the drain tube is not blocked;
4. Pull the exit drain elbow out of the sidewall. Clean out any blockage and clean up top end. If the exit slit is hardened, cut it away a bit to allow drainage;
5. Get a rubber extension piece that will slide over the end of the drain tube and into the top of the exit elbow. I found that a rubber spark plug moisture cover was perfect, 35 mm long overall, 15 mm ID for drain tube, 17 mm OD at other end for elbow. I cut away an inner ridge in the cover to make sure the tube could slide in fully;
6. Glue the end of the extension piece into the top of the elbow;
7. With rubber grease, lubricate the inside of the top of the extension piece and the outer flange of the elbow;
8. Slide the extension up onto the end of the drain tube;
9. Push the elbow exit through the sidewall till its lock flange sits neatly.
10. Reinstall covers etc, hope for the best.