Trunk leaks in heavy rainstorms. Trunk lid gasket looks good, without any tears. We put someone in the trunk and shined a bright light all the way around the gasket and couldn’t see any gaps. Any tips?
Give the light to the person in the trunk and turn on the water, have them look for the leak. The rear window may be leaking.
Thank you, we’ll try it!
Does the car have a spoiler? Water could leak where the spoiler mounts to the trunk or through the spoiler into the trunk if the spoiler has a brake light inside it.
A common place for water to get into the trunk on sedans is the tail lights. There’s usually some kind of sticky sealing material between the tail light ass’y and the place it mounts to. Check there, the sealant may be loose or coming apart. Especially true if the tail light ass’y’s have ever been replaced. The reason rain water can leak into the trunk there in big quantities is b/c there’s a water channel under the trunk lid that moves all the rain that hits the rear windshield and upper trunk lid around the edges and down & over the tail lights.
It’s best to try this at a car wash that has one of those high-pressure spray wands.
I’d check for leaks by applying water at and around the right tail light, first.
A 2 page GM TSB (Technical Service Bulletin written for GM technicians) #09-08-57-004B addresses water leaks in the trunk/spare wheel well of a few GM models, including 2008-2009 Chevrolet Malibu. The bulletin has a color diagram of the are with arrows pointing to places to look and reseal.
Apparently some of these vehicles possibly have body seams behind the right rear tail light assembly.
To reseal possible leaky seams one is supposed to remove both the light assembly and the rear bumper fascia.
I wouldn’t think those items are not too difficult to remove because while these vehicles were under warranty technicians were only compensated 0.7 hours of labor to remove them, apply sealer, and reinstall them. Most GM tail lights just have plastic wing-nuts in the trunk that hold them in place.