Rear drivers side carpet is wet and trunk is wet

[89-W-Body-Regal]

My 89 Regal 2 door has been leaking water inside on the rear drivers side carpet and in the trunk not to far where the radio wires are located. I lifted the rug in that spot and found out that it was wet and dripping water. The trunk also gets wet not to far from where the radio wires are located. Can this be a clogged floor drain or leaky body seams that have to be sealed? The rear windshield molding is also wearing off. So I was thinking if i used body seam sealant I would trap out the water from getting into the trunk than getting into the car. I think when the water from the trunk leaks inside it leads to the rear carpet somewhere. Someone said it can be leaking body seams or a drain. It just leaks in that one spot.so I'm hoping it's just body seams that to be sealed or weather stripping.

[rich_e777]

Do what I`m in the process of now, tear out all the interior trim and panels around your windows and sit in the back seat while someone runs a hose on the roof. You`ll find your leak pretty fast. You can also remove the exterior trim and seals and I`ll wager you`ll find a rust spot somewhere around the corners of your rear windshield. Also if you notice streaks on the inside of the glass that's usually a good indication water is trickling down the inside.

[89-W-Body-Regal]

the trunk is mostly the wet part which draws the water inside in that one spot. Do you think if I got body seam sealer I can try that? It's mostly in the trunk and only inside a small area of the rear drivers side carpet. I'll try what you said but if no water gets inside that way it could be the body seals in the trunk space.

[rich_e777]

You could also do the same technique on the trunk as well, it`d be easier to pull the panels out of it first, then crawl inside with a flash light. On my Cutlass I couldn't see how a leaky trunk seal could get all the way to the rear floor but the Regal may be a bit different. Have you ever had to replace the rear window?

[jman093]

The problem is not a drain. There shouldn't be water in the trunk to begin with necessitating a drain. You'll just have to find the leak. Pull off the trunk carpeting and blast the rear of the car with a hose and see where it ran in when done. Pay especially close attention to the left taillight. The lights sometimes stop sealing with age on 1st gens.

[jimmyfloyd]

I would wager it is either the tail light gasket or trunk gasket that is leaking before the window gasket. I just dealt with this on two other cars (non-GM).

 

On one, it was the tail light gasket. Remove the tail light, clean the gasket and body surface it attaches to. If it is ripped, try to locate a new one. If not, try a sealent of some sort. You could also run a bead along the whole gasket if necessary. I replaced the gasket on the car I fixed cause it was still available at the dealer for only $8.

 

On the second one, it was the trunk gasket... sort of. The car sat outside a bit under a tree and the channels next to the gasket had crap in them. Cleaned them, but some junk made it under the gasket enough to get the the pinch weld. The pinch weld in the low spot was separated just enough to allow water to come in. Removed the trunk gasket, cleaned it, the applied a silicon sealer to the top of the pinch welds and re-installed the gasket. A otrn gasket or shrunk gasket could do similar things.

 

Since the water is in the trunk, I would bet the issue starts there, and the water in the floor in the back is from the trunk. I would also check the inside of the rear wheel well, and look for rust holes or weak spots. On the Bonnevilles, they had an issue where the corner of the rear body would rust out, just under the rear seat corner in front of the wheel well. Because of the plastic body cladding, you'd never see it until you took out the back seat. not sure if the regal would have a similar issue.