So I've been reading all the threads about water in trunks and how they may be bad welds in the trunk tub, taillight seals and/or weather stripping and I've caulked everythign in site that I think could be a problem. When it rains I am still getting a little water into my trunk. It seems to be coming from the left side or driver side only. The top of my trunk mat is not wet and only the bottom side is a little saturated and soaks up water. The only place I think water could be coming from are 2 rubber plugs located on the trunk floor just below the taillight (about the size of a half dollar) with the letters "PVC" on them. I'm thinking that maybe my sunroof drain line is clogged and water is being backed up into the trunk. Does anybody know what the rubber plug labeled "PVC" in the trunk are for? I looked in the shop manual and can't find any reference to them but I do know the sunroof drain runs out the rear and to the bottom of the car in that general area. Are these access points for the sunroof drains? Can I access the rear sunroof drain by popping off the trim cover from the C- Pillar or does the whole headliner need to be taken out? Any help would be appreciated. Thanks!

 

I think those black plugs are access holes so you can get to the bumper shock absorber bolts. You cannot see them from underneath the car, so I seriously doubt those plugs are the source of your leak.

The sunroof drain goes down into the rear fender behind the rear wheel. Take off the inner fender trim in the trunk and put your hand down in there and see if you have water in there. The fender has a drain valve right behind the rear wheel that could plug up.

That said, I would bet that the tail light assembly is leaking. If you don't remove the tail light assembly and put the caulking on the tail light assembly, you will not stop the leak.

 

I already caulked the taillights and there was heavy rain this last weekend. When I checked there was no trail of water coming from the taillight but it seemed like those two plugs I'm referring to were damp and the trunk mat soaked up water above where those two plugs are. I'll probably pull those plugs and do some more investigation.

I thought it might be sunroof drain related because according from what I could decypher from the shop manual the drain for the rear part of the sunroof only runs down the driver's side.

 

As a test, take those plugs out and cover the holes with a piece of duct tape. It will take a good while before the duct tape will leak. I just don't recommend leaving the duct tape as a permanent fix.

 

step 1
get in trunk with flashlight

close trunk

step 2
have an assistant pour water over the trunk
use flashlight to see where water is entering

step3
research how to seal off water ( it will take the path of least resistance )

step4
repair or replace defective seals , spot welds, or failed component

step5

see step #1 to verify repair




Using this method i have fixed several water leaks in trunk