Interior Water Leak

[Rdr854]

Water leak is back. So, its back to the dealership again next week. Of course, its the rainy season here, and I have to park outside. The Yukon is wearing a "hat" on its shark fin antenna, constructed of duct tape, courtesy of the dealership, for now. The service adviser said they are doing a steady business repairing water leaks under warranty, many, many Tahoes/Suburbans/Yukons/Escalades/Silverados/Sierras are coming in, for the same exact issue, traced to the shark fin antenna.

What model years are impacted by the water leak at the shark fin antenna?

 

[JTRATX]

My wife thought the same thing. Although, the vehicle has never been parked under a tree, has been frequently washed, and is often parked indoors while I'm at work. I just find it unlikely that debris could block the sunroof drains. Anyway, it goes in on Tues, so we will see.

Test the sunroof yourself at home. Open the sunroof, and pour a cup of water in the front two corners of the sunroof tracks, you should see a tiny hole in each corner of the sunroof tract. If draining properly the water will come out under the A pillar on each side of the truck.

 

[wu6fiend]

The source of the leak was the shark fin antenna, again. Fingers crossed the second time to the dealership is the charm. This is a very common issue, I learned, including the 2015+ SUVs and 2014+ pickups. Keep an eye on the headliner on top of the A pillar, right above the plastic trim piece beside the windshield, that's where the leak will show up first, in my experience.

 

[wu6fiend]

So far, so good, dry as a bone. Coincidentally, my wife ran into the fellow that owns the company that just repaired my Denali. The dealership farms out this work to a company that specializes in repairing water leaks. He told her the central issue with these shark fin antennas is not the antennas themselves, but rather the surface they are mounted to. The roof surface is not completely flat (as it curves ever so slightly), while the antenna bottom is perfectly flat. Ergo, not a good mix. So simply replacing the antenna (which the first dealership did) will not solve the problem. The latest solution is to add a lot of sealant to the surface, prior to remounting the antenna to the vehicle. He said they are doing a steady business fixing GM's SUVs and pickups with these antennas.