Hello-

I have a 1985 300D with 308,100 miles on it that runs great and on Biodiesel for almost a year now.

I have had problems with water on the interior of my car for the last 4-5 years that occur when it rains on my car.

I'm fairly certain that the problem is external and not related to any holes in the chassis floor. I've heard that the vents on the hood or near the wheels can be a problem? There is plenty of rust on my car and I wouldn't be surprised if that was the problem but I'm not sure where it's coming from. the water almost leaks right out from under the steering wheel and under the glovebox also from below the large plastic kick guards.

anyone have any ideas?

Thanks, adam

Check your windshield seal, vacuum hose boots in the door jams, door seals, and the firewall, especially behind the battery.

__________________
2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Thanks for your reply. Any ideas on how to check these without dissembling anything? I'm fairly certain not much has been changed as far as seals and gaskets if it's not a moving part.

Thanks!

Sometimes you can see more in the dark with a flashlight.
Check the hood hinge "pocket" - there is a drain there (check both sides, of course).
Could be sunroof drain lines as well - I had one rust through at the corner where the tubing starts to enter the pillar.

Might be an idea to have someone pour water on various sections of the car, and have someone inside look for it. Pull out your carpeting first, and start from the bottom of the car and work your way up.

Good luck!

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

There are many, many threads to search on this topic.
Water infiltration could be from more than one source. Perhaps the Windshield seals and the sunroof drains, for example.

Here is a list of candidates to inspect in order of likelyhood:
1) Open window (Close the window)
2) Rear windshield seal (Remove and Replace (R & R) OEM seal)
3) Front windshield seal (R & R)
4) Sunroof drains (Use Heavy duty weed-eater string to chase the drains)
5) Bonnet(Hood) Hinge drain channels (ditto #4)
6) Firewall breach under Battery Tray (patch holes, paint)
7) Door weatherseal (R & R)
8) Antenna mount (R & R)
9) Hole in floorpan (eliminate H2O source, patch holes, paint)
10) Tail-light Seals?? (I suppose it is possible with repaired bodies. Frankly, I've never experienced a tail-light leak)

After the repair get the interior as dry as possible. Sponge, Wet-dry Vac and place moisture absorbers in trunk and cab. I suggest you remove the plastic trunk liners and dry out underneath to preclude or inhibit rust, mildew, and that Godawful moldy smell.

Motor on

__________________
Bama1


2008 SLK 280, Firemist Red - "Hurricane"
2001 F150 Lariat 4x4, Black on Black - "Badboy"
1982 240D 4 speed survivor -"Pearl" - Donated to Vietnam Veterans
1962 Oldsmobile Dynamic 88 -"Gertrude"

1954 model original owner - ~2.5M
Gray softtop/solid exterior/modified chassis

Thanks so much! My car has more problems than a math book but I love it to death, it's a work in progress. I'll check all those sources, thanks!

Pull your padded carpets (front and rear) for a week or so; check the floors after a rain. Feel the side carpets.

Get a black gutter sealant(50 year flexibility), and run a bead from 1/3 across the top toward the side, down, and back 1/3 toward the center. The manual actually recommends a sealant in this "C" shape on both sides of the windshield gasket.

I just did this and have had dry carpets since.

I keep my hood drains clear.

Also pull your cowl covers (black plastic grates) , and clear your drains. Push the center square pins down, pull the fasteners up, pull the grates. The driver's side drains right on top of a hole in the firewall.

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Peter
1985 300TD 4-speed 212K
1992 400E 343K
2001 E320 72K

Best way to check your windshield seal is to pull the dash and then sit out in the car when it is raining. This is probably the most likely cause.
The area behind/under the battery tray is very common for rusting through the firewall and will leak in a bunch of water. However, only on the passenger side.
Sunroof drains are also a known cause of water intrusion. [blocked drains causing a spill over]
I hear folks talk about the hood hinge pockets filling up but I haven't ever had that issue.
My guess in windshield seal. The dash is fairly easy to pull, then you can see the whole seal and watch it next time it rains.....

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Caution and With all due respect, the sealant suggestion above is very unclear and could lead to more problems by causing rust later on.

The improper application of a sealant on the outside of the rubber seal will likely trap moisture which can/will propagate corrosion.
Granted, a sealant may stop the water from entering the cabin but it should NOT be applied in this manner even as a temporary measure if you intend to actually replace the old windshield seal and depending on how much you value you car's paint finish.

If all you are concerned with is basic transportation & something functional to keep the water out, then this topical sealant approach may be your choice.

The alternative is to remove and replace the windshield seal and apply the sealant where it should be at the specific internal contact surfaces between the body and the seal and between the seal and the glass.

I'll try to find a graphic that shows it more clearly...

But yes, a good dollars to donuts bet is the culprit for your leak is a dead windshield seal.

Motor on

__________________
Bama1


2008 SLK 280, Firemist Red - "Hurricane"
2001 F150 Lariat 4x4, Black on Black - "Badboy"
1982 240D 4 speed survivor -"Pearl" - Donated to Vietnam Veterans
1962 Oldsmobile Dynamic 88 -"Gertrude"

1954 model original owner - ~2.5M
Gray softtop/solid exterior/modified chassis