GM sunroof care: Traverse, Acadia, Enclave
GM's big three-row SUVs share a platform and share its best documented sunroof problem: drains that clog or come up short, leaking through the headliner above the second and third rows. GM covers it in a service bulletin, and the fix is usually simple.
Clogged (or too-short) drains
Four drains carry water off the sunroof tray. The front hoses exit at the corners of the plenum, at the base of the windshield. The rear hoses route down the rear lower quarter panels, which is why a rear clog shows up a long way from the roof: a stained headliner over the second or third row, drips from the overhead vents or dome lamp, or water pooling around the spare. GM documents the leak pattern and drain service in TSB 10-08-67-001C, which spans the 2007-2016 model years of these trucks.
There is a second failure worth knowing: on early Acadia, Enclave, and Outlook builds some rear drain tubes were too short or slipped off, and GM ran a customer-satisfaction campaign adding tube extensions. So if a drain flows freely in a water test but the leak persists, check that the tube actually reaches its exit before blaming anything else.
Clear a slow drain gently from the top with a soft brush, then re-run the water test: pour a cup into each corner of the open roof and watch it exit underneath (fronts at the plenum corners, rears low on the rear quarters).
The tubes are a push fit, and on these trucks some were barely reaching their exits to begin with. An air blast can pop a tube off inside a pillar and stiff wire can pierce it; even GM's own service manual warns technicians about air pressure on these drains. Soft brush and water.
When it is not the drains
- The rear stationary glass bead. GM bulletin PI1061 documents voids in the urethane bead around the fixed rear sunroof glass on these models. Water enters at the glass itself, so the drains test clear and the headliner still gets wet. That one is a reseal, not a cleaning.
- A/C condensate drain. A wet front footwell that appears when the air conditioning runs, with no puddle under the car, points to the evaporator drain, not the roof.
- Cowl drains. Leaves at the base of the windshield overflow into the cabin air intake and the front footwell.
Water travels far from where it enters. Trace it up to the highest wet point and test one area at a time. See find your leak.