Another strange leak, this time trunk
 

Hey guys,



So I finally got my cabin water tight, and I've moved onto the trunk leaks. I have all of the trunk trim pulled out so I can track the leaks as best as possible. I've been using a hose over specific spaces to narrow down possibilities. I've fixed a leak on my passenger side tail light and got my rear windshield seal all sealed up and taken care of.


While doing some testing tonight, I discovered a new source of leak. This leak is on the driver side, where I had to seal the rear windshield seal. The windshield seal would show itself as drips from the rear deck onto the wheel well. This leak is different. While running water into the rear C-Pillar rain gutter, I noticed a trickle of water would make its way into the trunk. It seemed to start far up in the far corner of the trunk, and would come in via the little valley between the inside of the fender and the wheel well. I felt as far back as I could along the inside of the fender, but couldn't get my hand far back enough to feel the origin of the leak.

At first I thought it might be a loose piece of side molding, so I actually sealed the molding to the body with duct tape(temporarily) to test that. I ran the hose over the duct tape/molding for a good while and it did not leak at all. However, when I brought the hose back up and ran it through the C-pillar rain gutter again, the leak re-appeared. So I know it's not the molding. I couldn't get much in there, but I ran the hose with pressure along the trim and cleared all all of the leaves and crud I could. I should note that because of the direction/angle I was running the water through, it was not running over the windshield seal, trunk seal, or tail light seal. The water was running specifically into the C-Pillar rain gutter, down the gutter and out the bottom, flowing down the body and off the wheel arch. I got down and made sure the wheel well is in good shape, which it is, no rust holes. It seems the water is getting in behind the rain gutter.

What in this area has access to the trunk, that could be letting water through? I'm sure the hose runs a lot more water than normal conditions would, but I want to get this sealed none the less.

Thanks guys!

Well! I figured out how to take off that piece of trim over the C-Pillar rain gutter to check out the drain spot behind it and it appears the smallest little rust spot had developed(probably from stuck crud) and one of the PO's of the car was nice enough to seal it up with what appears to be your basic kitchen sink caulk. haha Shouls be an easy fix with the right treatment.

Are the sunroof drains allowing water to drain towards the side of the car properly? The C pillar is a known area for allowing water into the trunk when the sunroof drains rust out.

Why on earth the sunroof was ever invented I will never know....

The sunroof was invented, because it is wonderful
 

My car is now 22 years old, and the sunroof has never leaked. Even if it did, that's 22 years of enjoying the outdoors while driving, and a quick way to let heat out of the car during the summer.

As to leaks, I think your brake lights have gaskets that can allow water in the trunk area. Other than that, make sure your trunk lid seal is free of debris; that can divert the water into the trunk.

Yep. I checked those, they're all clear. This issue was in the little recess in the body that the sunroof drains go into. I got all of the caulking material the PO used to "seal" the hole out, so tonight I'll patch it in a more permanent manner. Everything else around it is in good shape and draining as it should.

Haha! Wish I could disagree with you. I rather often enjoy the sunroof on my moms W210, but that's a much newer car! I never even open the W123 sunroof.

Thanks for the tips. I'm all over the brake lights and what not.

Another leak point is the antenna.

water in trunk
 

get in the trunk with a flash light and have your wife shut the trunk and spray the water hose all around the trunk untill you find the leak, ps tell her not to leave you in there.