W123 leaks water in rear passenger footwell

[hessam69]

Hi everyone,



I have just come to realise after a bit of heavy rain for a few days my left rear passenger footwell is flooded, I took out the mat and there is about half inch of water sitting in there


Its a 79 W123 sedan


My car has a sunroof but I have driven it in the rain and there doesn't seem to be any leaks, also since the front footwells are completely dry, I think it's either a window seal or the c pillar vent where dirt and leaves usually get trapped, I washed my car before all this happened and tons of dirt leaves and mud came flying out so that was probably blocking the hole or whatever it is that was causing the leaks..... Unless you guys have more ideas?



Thank you

[pselaphid]

This was covered over in the diesel forum recently and I've had the same problem. Check the front passenger hood hinge drain. Water pools up, runs through the firewall and finds its way to the rear floor.

[rs899]

Check under the battery. You may have burned a hole through the firewall there.

Most likely a window seal though.

[rebreath]

mine was neither of those,it was instead the rusted hole below the seatbelt mount.B pillar at the bottom,under the carpet

[meltedpanda]

bad seal in the window should shut water to the door and then out drain holes in bottom of door, so check those make sure they are not plugged. Place a strong light under the car when it is dark and pull up mats ,rear seat, look for those oh so present pin holes!

[JimFreeh]

Don't forget the windshield seal.

It's not the back window. That leaks into the trunk....

Jim

[Mr.Kenny]

Do a search on this common problem; this way you will find where all the leaks can originate.
Nip it! Nip it in the bud!

[280EZRider]

The R hood-hinge drain is a possibility, but most likely there is a leak on the R side of your windshield seal. This is very common on the W123. The rear footwells are lower than the fronts, so water from the front will always end up there - and even under the carpet with no trace on top.

[Mark DiSilvestro]

I've had a couple W123s where the firewall, just below the hood-hinge drains, rusted through behind the rubber undercoat, resulting in water in the rear footwells.
Tough to fix. Requires going inside the front wheelwell, peeling off all the loose undercoat, trimming & cleaning up as much rusted metal as possible, then patching & resealing. Since doing this to my 300TD last summmr, I haven't found any more wetness on the rear floor.
Also seen them rust-though the firewall behind the battery tray, but that's an easier fix.

Happy Motoring, Mark