Water leaking into the boot

[Junior92]

Hi, I've had my MB6 for 3 years now and it has been stood for last 2 years. I just got the car out recently and got so much work to do, but first need to sort the leak on the roof and spare wheel area in boot. Both the roof and boot leaked ever since I got the car but I did manage to fix the roof leak but now it is leaking again and I never got to find the cause of boot leak.

 

Here is what I have done so far.

3 years ago when I first got the car, I noticed the roof lining from front drivers side corner was wet. So I removed the roof lining, removed the sunroof drain tubes, poked a metal wire in. I then removed the roof strips and found a small hole on front driver side (where the roof lining was wet). So I applied lots of tiger seal to block the hole and also along the whole roof strip area on both sides then fitted back the roof strips. I never put back the roof lining and for a year and half my roof never leaked.

 

I then moved onto the boot so removed the tail lights, removed the tail light seals and applied clear silicone on both sides then put back lights and tightened up. I also removed the rear bumper and applied silicone onto the vent/flap thing from outside and also inside. This still did not fix the leak onto the boot. 

 

Now 2 years later, after moving the car. I have found the rear half of my roof is wet and also the boot spare wheel area is rusty. I have examined the boot leak and I suspect it is leaking from two areas. On the passenger side, just next to vent/flap thing, there is what I believe it passenger rear sunroof drain tube which is where the leak starts from. There is also a little bit of rust around that area on the arch but the car has been parked up so I doubt it could be the arch. Are the sunroof drain tube prone to cracks over time? I have attached a picture to show you what I mean.

 

Now on the driver side, it's difficult to explain but after lifting up the boot seal, I found a bit of rust which is where I think it may be leaking from. I removed the boot seal completely to check if there is any rust anywhere else but thankfully nope, just on where I suspect the leak is.

 

I also noticed that my tailgate hinges are rusty and cracked, could it be that water is passing through them causing the rear half of my roof to leak? Any help would be appreciated

 

 

[martinw]

i,

had a very similar problem recently on my mc2 aerodeck recently which took days/ weeks to source.

At first thought the source was low down and applied mastic to various seams but still didn't source it. Eventually, (after drying the area up every day) realised that the water was entering quite high up, probably inside a sealed interior panel. 

On my car, the next highest panel upwards included the boot side widows so had a look and the seal to the window looked perished on the top edge, so applied mastic to that top edge ( you need to apply masking tape to the painted areas around before you do this) and after a few days the leak stopped. In your case this is complicated by the the rust around the hinges but still, look higher up than you might think for the source of the leak......

[dr_broon]

1 hour ago, martinw said:

i,

had a very similar problem recently on my mc2 aerodeck recently which took days/ weeks to source.

At first thought the source was low down and applied mastic to various seams but still didn't source it. Eventually, (after drying the area up every day) realised that the water was entering quite high up, probably inside a sealed interior panel. 

On my car, the next highest panel upwards included the boot side widows so had a look and the seal to the window looked perished on the top edge, so applied mastic to that top edge ( you need to apply masking tape to the painted areas around before you do this) and after a few days the leak stopped. In your case this is complicated by the the rust around the hinges but still, look higher up than you might think for the source of the leak......

I've just had those windows resealed on my deck, not sure if it's sorted my leak though... Hope so as I've just had all the rust cut out and welded. 

[MBFinlay]

Same thing with my MB6. Water gets in the left side like in your second picture. Next to that white "ventilation" thingy.

[martinw]

Spoke too soon !

After a night of frost and the front end up on ramps, the water was back in the drivers side rear wing.

Looks like the change of angle the cars sitting at had exposed another area of bad seal.

So, as I have only partially sealed the rear boot window, looks like I will have to do more.

As I had put the spare wheel back in, decided to check if any water under there. And there was ….

Traced where this water was coming from and it was entering from the seam where I,ve shown on the fist pic.

As couldn't tell from inside if there was a hidden closed panel where the water was sitting, decided to remove the rear bumper and the second pic shows that there is no exterior seam or hidden closed panel in that area.

The only closed panel where water could sit and then enter the boot is the panel below the boot lock shown in the 3rd pic.

Bit of a mystery this - shone a torch around the boot lock and no sign of water sitting there, but cant see much in there and there were signs of mud, probably from a previous wash of the boot/trim. 

One thing though, this closed panel connects to the closed panel running up to the rear windows so.....

I could just seal that seam inside the boot but it worries me that the water could still be sitting behind it 

 

[KiNK43]

Touch wood I think mines ok now. Had a leak in Footwell was soaked. Replaced the seal as was ripped holding water problem solved..

Just keep it in garage now in this weather.

I still think the rear window seals are often the issue on aerodecks

[Dave]

Water only ever travels down mate, so it could be either coming in around the rear load lip due to the boot hatch seal. Could also be the rear sunroof drains are blocked (although be buggered if I could ever find them on these!) as this allows water to run down the inside of the c pilar which would lead to where your seeing the water. Think as Jake also says, the sealing around the two rear side windows if gone would allow the water into that same section. Not sure if running sealer round them on the inside would be effective as they're fitted from the outside using bond. Might be worth having a search online (youtube etc) to see if you can remove the rear windows without breaking them. if you can, would be worth redoing the bond and putting them back in. Bit of a pain and a bit of work but much better than having to get the car welded if the water rusts her out (which it will eventually).

[dr_broon]

18 hours ago, Dave said:

much better than having to get the car welded if the water rusts her out (which it will eventually).

I can vouch for this.... 

[martinw]

See dr_broon's later post about body seams under the roof gutter rails allowing water in, that makes it's way to the back of the car inside the body. One that I will be checking as my leak still isn't fixed.