My trunk is leaking on my 85 Delta 88.

Floor pan of the trunk is in good shape. No rust or holes. Cleaned a lot of crap from around the trunk seal and it has gotten a lot better, but it's still coming from somewhere.

The water is pooling at the back of the trunk, I see water trails from around the spare tire area but it's bone dry right above it. The inside of the trunk seal is dry all the way around, but on the outside between the rubber seal and the quarter panel you can see where the water is running off correctly.

We had 2 inches of rain Christmas Eve little bit of water. Had about 3 inches last night, a little bit more.

Any common areas I should look for? My old one didn't leak at all

 

Get in the trunk with a flashlight and have someone spray it down with a hi pressure hose.

 

Leak around the back window??

 

Was thinking that, but kinda want to avoid that route

My mom suggested that when I told her the trunk was leaking, I dismissed it, but I might have to take a second look

 

My Caddy get water in the trunk if tree debris causes dams in the channel next to the weatherstrip. The water rises and seeps in. This baffled me for a long time. Looks like you checked that already which is good.
I assume you have no sunroof...

 

It can also leak in around the taillights. My wife and I have a funny story from over 40 years ago when I had a 65 Grand Prix that was leaking in the trunk. I was in the trunk with the flashlight and she had the water hose. We were talking back and forth when the little lady walked up to visit a neighbor. You can guess the rest of it. I did find a leaking taillight.

 

No sunroof.

Yes that channel was completely blocked right in the center, probably the lenght of the center mount tail light (I know they came out in 87, but I put one in from an 88 Caprice. I needed a new back deck carpet and for $5 for the combo, including all the wire I needed and the grommet, why not ). I did notice two little spots on either side that damaged the trunk lids paint very little. I can't find my air gun, but the channel is 98% clear.


It's less water, but it's still there. 2 paper towels per puddle.

 

i have a 76 grand prix doing the same thing, so i replaced the weatherstrip as it was original and flattened and upon washing the car afterwards, still doing it. oldcutlass is right on with the light and hose approach- when i do it, i'll take the side panels, spare and carpet all out as with a bare trunk and a cordless droplight, you will find the culprit for sure and it could be more than one. on the pontiac, it turned out to be dripping from the metal seam between the panel that goes underneath the rear window inside the trunk and joins the quarter panels there. so unfortunately the vinyl top will have to come off and rear glass resealed as long as there are no other surprises.. before taking everything out of the trunk to check, i was baffled because no apparent leakage in the spare tire area.. well the spare tire well is raised slightly and the water was running right off the edge where it drops off and collecting about four inches in front of the tail lamps. at first i thought those were the problem. redog i hope you have better luck and an easier fix-