W.E.G.

Car has been parked for several days while we've had daily rain.

I notice that the carpet in the rear cargo well is considerably wet.

Nothing imediately apparent around the rear hatch seal.

I need to pull the carpet and chase the source.

Any experience from you guys as to the probable source?

Drew

iTrader: (58)

Well... Get it? Well? Oh well...

This is fun because there are a million and one places back there for water to get inside. The first place to look is the weatherstripping. People like to adjust the pulldown assembly, sometimes too tight, which can crush the weatherstripping and cause it to go flat. Also, keep in mind that water likes to wick under the weatherstripping and rust the flange the weatherstripping bites onto. Also if the hatch pulldown doesn't work, the hatch might not be closed all the way...

The next thing I'd look at are the plastic filler pieces where the rear edge of the hatch glass meets the decklid. To get a smooth transition, GM snapped these little plastic fillers in place, and globbed the works together with urethane. If the decklid has moved, which is common on thirdgens, the urethane may not be sealing, in which case water can wick through between the gaps and drip in the hatch well. Likewise, any leak between the glass and the decklid can leak inside the car.

Butt weight! There's more! Got a spoiler? The spoilers bolt on, generally the nuts are sealed at the factory, but if it's ever been removed, or if the sealer has dried and cracked with age, they can leak. On a related note, all thirdgens have a HUGE access hole behind the tail lights for access to the top spoiler stud on the typical 3pc Camaro spoiler. On cars without the spoiler, GM popped in a rubber plug like the ones across the bottom of the decklid. You guessed it, the plugs can be missing, damaged, etc and can leak.

Tail lights... All the mounting studs were sealed originally, but might not be sealing now. The same applies for the holes where the tail light wiring harness passed through the body exiting on the driver's side, and entering on the passenger's.

If you had a Firebird, the rear marker lights in the fenders would be worth a look too.

Hatch bolts... The ones from the hinges to the body at the back of the roof under the headliner trim panel. The ones through the glass, you'd probably notice them leaking.

And finally for my favorite! The huge, ridiculous wads of seam sealer. Open the hatch and look at the top corners of the body. Where the quarter panels meet the roof skin, there's a joint and seam sealer on both sides of the car. If these leak, you probably wouldn't notice since it'd run down inside the 1/4's in front of the rear wheels and drain.

Then again at the rear of the hatch opening where the 1/4's meet the tail panel, you'll see another seam, with sealer. If this leaks, you'll get a bit of water in the trunk, but it'll probably stay behind the panels.

The next one is probably much more applicable on the Firebirds because of how the tail lights fit the body, etc... But as the 1/4 panel comes back, and wraps around the tail panel, as an extension of the seam I just mentioned, there's a HUGE gap hidden under a little plastic trim piece retained by a Torx screw. If you remove that cap, GM forced about a metric ****-ton of sealer between the panels and molded it to shape like a 3D mashed potato sculpture of Devil's Tower. If that sealer gets old, dries out, and cracks or shrinks away from one panel or the other, water will wick into the joint and into the trunk.

Honorable mentions -
The gap where the trunk weatherstripping meets above the trunk lock.
The trunk lock.
The metric ton of sealer between the top and bottom halves of the trunk well, and on both sides - usually only applies if the car is driven in rain.

I could also see really leaky T-tops potentially leaking enough inside the interior panels to reach the trunk, but that's a stretch.

Of course the real gotcha of all of this, is that if the drains the factory punched in the body in key places are free to drain, most water coming in will flow right back out. The exception being the well, which is fairly water tight. The wading pool in the trunk of my project car was a combination of several leaky sealers, weatherstripping, and a busted hatch pulldown.

W.E.G.

This is a very helpful checklist!

Motivates me to dig in!!!

Bddbrd86

My 86 Firebird has a small rubber plug in the rear well to drain the water. I just left it out till I found my leak.

Grandpa

You said that the car sat during the rain right not driving, then you noticed the water. well I'm going to save you a lot of headache go to the parts store and buy you a big tube of flowable windshield sealer it is clear. Now take you a good rag and go to that stupid metal trim around the back glass clean it very well all the way around and across the bottom at the lid part. and if you can get the plastic covers off of the top mounting bolts too. Once cleaned start with the lid open and at the top center of the glass to metal trim start applying the sealer. If you have someone to help it's easier to control the lid as you work around it. But the key is to let the sealer flow into the cracks and create a continous bead all the way around the glass and lid. I bet you will have no more leak. Mine done this same thing back in 2004 and I haven't had anymore water in the trunk since. Just make sure you do it when the temperature is above 70 or better so the sealer flows easier.

GeneralDisorder

iTrader: (1)

It's usually the deck lid. You need to dissasemble it and reseal the deck to glass interface. I had my windshield guy do it with hot urethane. Bone dry now.

GD