Waterleak in boot B Class

[Cartraveller]

Hi, I'm the proud owner of my first Merc - 2008 B 200 CD1 , my first automatic. Brilliant car.
Just one small fault, when I checked the spare wheel well it contained at least a gallon of (clean) water sloshing about. I took liner out, dried it. Left it uncovered for about 10 days. Car left outside and it remained dry, even when I drove it for 200 miles. Then today, after heavy rain, drove 5 miles on wet roads, through puddles, & already have half a pint of (clean?) water in the well. Obviously it is move to the front lowest part, but also wet in centre rear part of well, so it may be coming in there.
Any ideas. Seals around the boot seem fine and dry.
Any ideas much appreciated.
Thanks, Richard

 

[ajlsl600]

Do you have a sunroof ?

 

[Anthony Humpherson]

Hi, I'm the proud owner of my first Merc - 2008 B 200 CD1 , my first automatic. Brilliant car.
Just one small fault, when I checked the spare wheel well it contained at least a gallon of (clean) water sloshing about. I took liner out, dried it. Left it uncovered for about 10 days. Car left outside and it remained dry, even when I drove it for 200 miles. Then today, after heavy rain, drove 5 miles on wet roads, through puddles, & already have half a pint of (clean?) water in the well. Obviously it is move to the front lowest part, but also wet in centre rear part of well, so it may be coming in there.
Any ideas. Seals around the boot seem fine and dry.
Any ideas much appreciated.
Thanks, Richard

Hi , I know it's not the solution for the rain getting in. But I have drilled a few drain holes in the wheel well in other cars I have had that problem with. Being careful of any cables/or pipe work underneath . Regards

 

[EmilysDad]

Hi, I'm the proud owner of my first Merc - 2008 B 200 CD1 , my first automatic. Brilliant car.
Just one small fault, when I checked the spare wheel well it contained at least a gallon of (clean) water sloshing about. I took liner out, dried it. Left it uncovered for about 10 days. Car left outside and it remained dry, even when I drove it for 200 miles. Then today, after heavy rain, drove 5 miles on wet roads, through puddles, & already have half a pint of (clean?) water in the well. Obviously it is move to the front lowest part, but also wet in centre rear part of well, so it may be coming in there.
Any ideas. Seals around the boot seem fine and dry.
Any ideas much appreciated.
Thanks, Richard

this is the reply I gave to someone else recently re my then R Class ..... a B Class seems similar in the boot lid area.

Completely different car .... but the water entering the spare wheel well of my R Class was getting into the car via the chrome trim across the tail gate. The trim was screwed into ally captive threads, the ally had corroded & were loose in the tailgate which meant that the chrome trim was also loose, water found its way around the trim & into the tail gate. Water would pour from the trim around the rear window when the tail gate was opened. Took me ages to find it.

Your car might be similar ....

 

[ZZZZ]

It's the air vents behind the rear bumper - the [rubbish quality] seal around them deteriorates and water gets in.
Same problem across the W169 / C169 / W245 range.
Solution is to take the bumper off, remove, clean and re-seal (Tiger Seal or similar) the vents (I did away with tiny silly cowls / visors too - they're not fooling anyone and absolutely useless).
Not a hint of damp since.
There are a few threads on the subject on this and other forums, with pics, etc - include 169 in your search.

 

[ZZZZ]

Couple of pics I pinched from [mostly] Canadian forum about four years ago:

 

[Cartraveller]

Thanks for replies.
1.There is a sunroof but it doesn't open. Poured water over roof but cannot see any ingress.
2.Removed the rubber seal in front offside (see photo) and let water drain out, but it did not all drain away (a good seal underneath!). Left it overnight and some more (clean) water appeared.
The higher part of the well, to the rear, seemed wet as though it's coming in from there and then finding the lowest point.
I think I will order the air vents behind the bumper as GLK suggests. Are they both the same? I have found a supplier who sells a pair.
Forgive my ignorance! I've tried to buy a Haynes Manual and it says not available yet!

 

[David Richardson]

Deffo the air vents behind the rear bumper, this is a common fault & very very well written about on the
https://www.aclassclub.co.uk/

https://www.aclassclub.co.uk/threads/help-with-water-in-spare-wheel-well-w176.8559/#post-88421

Drop in & search water in the spare wheel well, the cost of the replacement vents is IRO £15 per side, the problem is that you have to remove the rear bumper & of course dry out the soggy carpets before they smell like a wet dog

 

[Cartraveller]

Deffo the air vents behind the rear bumper, this is a common fault & very very well written about on the
https://www.aclassclub.co.uk/

https://www.aclassclub.co.uk/threads/help-with-water-in-spare-wheel-well-w176.8559/#post-88421

Drop in & search water in the spare wheel well, the cost of the replacement vents is IRO £15 per side, the problem is that you have to remove the rear bumper & of course dry out the soggy carpets before they smell like a wet dog.

Thank you, although mine is B Class, it sounds the same problem! I'll order the parts, have already dried liner and not refitting it until it's fixed.

 

[ZZZZ]

I fixed mine without ordering the new parts, although it did involve a bit more work

 

[Cartraveller]

Thank you fellow travellers, I received the parts today and attempted to remove bumper. I Undid 4 retaining screws holding plastic cover underneath, removed the rubber seals and the four screws holding lights and bumper from behind. Result: Loose but not removable. There are two larger nuts inside , approx 17ml, (see photo - the view is from inside wheel well, looking back out of the car) do these have to be removed, They seem rather substantial for holding just the bumper!
I have looked at other links, and tube videos, but nothing I've found is quite the same.

 

[ZZZZ]

Here's the relevant WIS file: