Water Ingress In Boot On My W211, E/Class !

[JCBman71]

Hi Everybody, A Couple Of Things To Ask Advice On !
Everytime we have Heavy Rain, My Boot Area Is Letting In Water Somewhere, But I Can’t Find Where !
All The Surrounding Rubbers Are Good, But Water Is Getting In, And Particularly InThe Spare Wheel Well !
Can Any Body Advise On This Problem, Somebody Has Suggested, That There Might Be Some Sort Of Hidden Vent, Behind The Rear Bumper, The Same As A Lot Of Volkswagen’s ?
Also, Having Owned This Immaculate W211 E/Class For Nearly 8 Years, inspite Having New Batteries, If The Car Stands Idle For A Few Days, The Battery Drains, And I Have To Jump Start It !
Can Anybody Shed Any Light On What Might Be Causing This Problem ??
Many Thanks In Anticipation Of A Responce !!

 

[m80]

For the ingress,
while I'm unfamiliar with the saloon, if you have a roof antenna it's worth looking at the cardboard liner below, to see if there is evidence of it being wet.

 

[JCBman71]

Thankyou, But There Is No Roof Antenna, !

 

[MrGreedy]

Wherever you are looking, around the back of the rear light seals, around the boot trim etc, dab around with some blue tissue/shop towel. This will really show up a single drop of moisture as dark blue so it's easy to have a look and see after each dab. And a single drop of moisture found higher up away from the place where the water collects could be the source of the leak.

Obviously you will be dabbing the areas higher up with all the seals/joints (no matter how good you think they might be) just to do this quick check. No point using the blue tissue to wipe areas that are soaked, as you can see/feel that is where water is collecting anyway.

 

[OneForTheRoad]

Does water slop out of the boot lid from either corner when you open it ?? Possible entry points I've circled,rear lights and 3rd brake light, the dotted line is best sealed up with puraflex or silicone , or if your upto it ,remove the number plate surround , renew all popper clips and sealing rubber rings , there are around 20 off the top of my head . Anyone can leak . They get mouldy and go hard . There's also a small drain in the middle of the boot lid rubber , under the number plate in the middle.

There's also the main seals and scuttles inside the boot that needs a clean and reseating with puraflex.

Battery has a parasitic drain possibly, it would need to be checked by an auto electrician.

 

[gusferlizi]

Don't stress over it, just bite the bullet and replace ALL sealing components.

~£200 from Mercedes

Boot seal, boot water guides, rubber rivets, light seals, etc.

Believe it or not, it will also trickle under the old big seal at this age, so you want to prepare the metal lip and rust convert any rust.

I can show you if you're close to London and swing by

 

[W1ghty]

I had this with my W211 saloon as well .
I had removed the rear lights and used black RTV sealant on the foam seals that were failing before reinstalling them .
I also changed the drain channels

New Boot Trim from MB Grangemouth Parts

Bit the bullet the other day and rang MB Grangemouth (Parts dept) for some new rear boot drain/trim parts . Fearing that worst , I left Euan with the job of deciphering my email pictures as to which bits I needed . He came back to me with the grand price delivered of £24 ish . The parts...

forums.mercedesclub.org.uk

As above though , cloths or talc may show the route the water takes .
Good luck

 

[MrGreedy]

Believe it or not, it will also trickle under the old big seal at this age, so you want to prepare the metal lip and rust convert any rust.

What do you mean by 'the old big seal'?
Do you mean the full boot seal? and when you pull this off the metal lip it sits on, it's common to find the lip a bit rusty that will need treating first?

 

[gusferlizi]

What do you mean by 'the old big seal'?
Do you mean the full boot seal? and when you pull this off the metal lip it sits on, it's common to find the lip a bit rusty that will need treating first?

Yes the rubber compresses and doesn't seal as tight. Often leaks under the seal bead itself towards the bottom where it turns; when it gets yanked by something, or after it gets pulled out when chasing a leak (creating a bigger one).

The new seal will have a fresh jointing compound inside and the metal lip needs to be clean for it to mate properly.

 

[Dryce]

Everytime we have Heavy Rain, My Boot Area Is Letting In Water Somewhere, But I Can’t Find Where !

Previous tread on this might be helpful: W211 boot leak | Bodywork