I own a 2016 Chevy Express and have noticed a few times when I have the back cargo doors opened that water drips out from under the large black trim piece that holds down the mat. About a week ago I snapped off the trim piece and lifted up the cargo mat and it was completely soaked. I tried drying it out as best that I could (it was still pretty wet). Today I noticed more water dripping out so I lifted up the mat again and it was drenched again. It is from rain and I don't feel any water in the front. It didn't raid when I was driving but rained yesterday when it was parked. It really has me stumped.

 

Do you have warranty? If so you'll want to invoke it. Water leaks can be a huge PITA.

 

No warranty, it's up to me. I will probably have to pull all the shelving out to even start to figure this out unless someone has experienced this before.

 

I'd check the door gaskets. I've had issues with a couple of vehicles (not my Express (yet)). In one case, the gasket just kept popping off, so as long as I kept an eye on it and popped it back on, it was no problem. The other issue was my Astro, and the gasket was just bad. Replaced it and no more problems.

 

I had a leak. I got it fixed professionally. I thought I knew where it was coming from, but it turned out to be somewhere far away and completely unexpected. I recommend going to a professional, but if you're set on doing it yourself, be prepared for months of trial and error. Two body shops turned me away because even they don't want to deal with leaks. Even though I didn't pay for the service, in hindsight I would happily pay the few hundred bucks to get it done anyway.

- Start by washing the vehicle really well so you get rid of any dirt or mildew that might be hiding cracks. Inspect all the exterior seams, from front to back. Water will travel a long ways.
- Remove interior trim. Douse the van with your garden hose, and poke around inside with a flashlight. You'll need to try this with the van inclined in all four directions. Sometimes the leak doesn't show up until you start driving because the air flow pushes it in.
- There is a pressure vent behind the passenger side tail light. It looks like a louver window. Seal it up. Shut the doors and windows. Then blast air from your vents on full power. Start spritzing the outside of the van with soapy water, especially around windows and seams. Look for bubbles. You mean even be able to hear/feel air rushing out.
- When you find the leak, you may need special products to repair it or it will come back. Some body gaps are quite wide, and vehicle bodies flex quite a bit.

Best of luck.

https://chevroletforum.com/forum/exp...of-leak-84279/

 

Good advice with the positive air pressure.

Just a note. My 2015 had two pressure vents. My 2014 has one. I do not know if that was a 'year' change or a 'body' change (dual doors).

 

Thanks for all the ideas, not sure when I will be able to do it but Winter seems to have showed up all of a sudden

 

Today while backed down a hill again, I had water dripping the entire day from the body panel seem just above the tail pipe. I have checked the weather stripping on all the doors and they are all in place and still look new. I have noticed since I have owned the van that the sealant on the gutter area or where the sides meet the roof that it doesn't look like it was done from the factory and also found the same looking stuff at a welded seem under the cargo mat. I wonder if the previous owner brought it to the dealer and they did this as an attempt to fix it but didn't succeed. I had a 2000 express and the roof sealant was smooth.

 

I'm sure it's factory. Welcome to the new GM.

So what are you going to do?

 

Still working on it, I think I am going to have to take some of my shelves out of the back and fold back the mat and start running water on top and go from there.