Sunroof leak

Denali James · October 27, 2016

It's never fun to be in a automatic car wash and 1/3 the way finished when all of the sudden water and suds pour in through the sunroof. Just on one side, front left. After the wash completed and was free from the wheel track system and about 3-5 gallons of water and suds later... I inspected the sunroof to find the accordion seal was jammed in the area where the water came from. I opened the sunroof and the seal fell down into the soaked compartment. Headliner, seats, dash, radio display, and myself were all soaked.

Drove straight to the dealership for repair...5-7 days estimated to fix the issue.

I am not happy.

JimCost2014 · October 27, 2016

don't think the seal that you are describing had anything to do with the leak. it is just there to hide the "guts" of the sunroof track. more thank likely it is the shark fin or the seal (gasket). I had leaks in my 2008 and 2014, from both sources. the 2008 was one and done with the gasket being the problem, the 2014 was both and numerous fixes to get both right. good luck, t will get fixed.

DenaliHD · April 5, 2017

Sunroof leaking yet again...NOT HAPPY!!!

After taking it in for repairs, I have opened the sunroof a dozen or two times 2 months after being serviced at the dealership.

Last Sunday morning it was pouring down rain for 3-4 hours.

Went to get in to go to the store, drips coming from both sides of the control header above the rear view mirror. The headliner was soaked from about mid driver's seat to the center overhead console on both sides. Center console had water up to the top of the rubber cushion at the bottom of the console well. Both front seats were wet (leather heated and cooled).

I ensured the sunroof was closed and have driven days earlier in rain with no leaks. (I am the only driver). I did not open the sunroof in the past month prior to this event.

I have not checked the shark fin seal.

pogrelis97 · April 6, 2017

Curious if most people who are experiencing a leaking sunroof leak leave their trucks parked outside?

DenaliHD · April 7, 2017

I can't park my Denali in the garage due to the garage being built too short in length to accommodate my Denali HD.

Mike Hamm · April 8, 2017

Curious if most people who are experiencing a leaking sunroof leak leave their trucks parked outside?

Curious as to what you are saying here? I'd like to reply, but want to understand what you are asking before I do.

EJCarter · April 9, 2017

Never had a leak...and I use the rear-tilt feature whenever it's not raining or too cold. Truck is parked outside daily and we definitely have had an increase of rain this past winter in California.

dasimmon · April 9, 2017

hope they get it fixed

pogrelis97 · April 10, 2017

Curious as to what you are saying here? I'd like to reply, but want to understand what you are asking before I do.

Just wondering if sitting outside in the elements full time has something to do with the sunroof being prone to leaking. My truck is parked inside and doesn't get driven unless the weather is nice so I'm just curious.

Mike Hamm · April 10, 2017

Just wondering if sitting outside in the elements full time has something to do with the sunroof being prone to leaking. My truck is parked inside and doesn't get driven unless the weather is nice so I'm just curious.

Maybe? But, I'll answer it this way. We have a 15 year old Nissan Maxima that had never been garaged up until starting a year ago. Most of its life was spent in San Diego with very hot summers, higher UV index than here, and some freezing nights during the winter. No seals leak. We only started garaging it a year ago because we now have a house with a big enough garage for it and all our stuff. Both of my Nissan Frontiers were never garaged. Also, never leaked.

Pickup trucks are meant to be used and used outside in good weather or bad. And, understand that the sharkfin seal that is leaking is inside the sharkfin and not something really directly exposed to the elements. So, it really should last longer than 8 months (in my case). Now GM says that inner seal is too small so they are now installing a bigger one. It seems to be a well known design defect that should have been addressed at the assembly line level and not via their customers. The real problem is the gap in the outer seal. It lets water in and there is nowhere for it to drain out so the water just builds up inside until it overwhelms the inner seal. Parking it in the garage and only using it on sunny days just isn't how I use mine and it shouldn't be the way anyone has to use theirs. Hopefully the 2017 models won't have this problem.

I know you asked about the sunroof seal, but same sentiments apply regardless of seal.

Edited April 10, 2017 by Mike Hamm

DenaliHD · April 11, 2017

I have "water checked" the shark fin myself with no leaks. My driveway does have a slight slope to the left in my normal parking spot. I will re-attempt the "water check" again in the "normal" spot on my day off.

I am confounded on this issue as it has rained hard here today with no leaks on level ground.

I know it was fully closed before this second leak, before exiting my truck I have made it a habit to push it to the closed position on the switch after the first leak.

I can only deduce that the current seal is: there is a defect in the seal itself.

I have had sunroofs in other vehicles and they never leaked and they were not garage kept.

DenaliHD · May 7, 2019

With an unusually wet 2019 spring here in Arkansas, sunroof/shark fin leaks still leaking. So very pissed off at GMC for this design flaw.

I have taken the truck to the dealership so many times they know everything about me before I get out of the truck.

Now the floor board and carpeting is ruined as it is soaked. I showed how much water was coming out as I used my hand like a squeegee on the carpet. I left it with them, after two days, they called and said that I needed to have the carpet cleaned and dried as they could not locate the leak unless it was dried out. They even said with the amount of water in the carpet that I must have left a window open.

Took the truck to have it cleaned and dried out. Was told by the detail shop that I was one of many people that had the same problem.

Took the truck back to the dealership for their “water leak check.” Later that same day they called and said that they suspect it was the windshield after I had it replaced after a rock flew up while driving and cracked the windshield.

I took it back to the place that replaced the windshield to have it checked or replaced.

it passed their inspection.

I took it back to the dealership on a day it was raining and yes, it was dripping from the roof console and sun visor clips. Carpet was soaked again. Now the mildew smell is horrible and almost unbearable.

If this is what you get for buying a $70k truck, GM can have it back.

gearheadesw · May 8, 2019

What a total drag. I would be fuming, what did they say when you brought it in while it was as dripping from the rain? How many times have any dealerships looked at the same problems? They may take it back, with ruined, moldy crappy carpet, right?

DenaliHD · May 9, 2019

The dealership said that they suspect the drain tubes were clogged. They checked it out right there in the service bay by pouring water in the front corners. The water poured out from behind the front tire wheel wells. They suspected that it was the satellite shark fin or possibly the third eye brake light. They didn’t have time to look at it and needed to make a follow up appointment.

I have since taken some clear silicone and went around the shark fin and third eye brake light and had the carpet cleaned and dried. Smell is gone somewhat now. Looking to buy some thin rounded rubber weather strip to go around the three sides of the sun roof. If all else fails, deactivate the sun roof and silicone the gap between the roof and the glass.

I’ll never buy a sun roof vehicle again.

Dick Longfellow · May 30, 2023

Roof leaking first noticed last year while camping on my 2015 Denali 2500HD, with a sunroof. Dripping from overhead and down by emergency brake whenever I washed the truck or it rained. I returned from Mesa back to Canada mid-April with a taped up sunroof to eliminate THAT leak while down there. To fix luckily I have a "Jimmy" who loves to solve car issues. We took off the side pillars, easy enough with a few screws, dropped the liner and found the drivers side hose not connected to the drain, front corner of sunroof. No wonder it leaked. Checked the other 3 corners and they were all secure, but we twist wired the connections so they don't fall off due to evil spirits. As others have said make sure they drain properly outside by pouring a little water in each corner before sealing up. Poured the hose to the roof for a few minutes, no more leak! This check should be done first before looking at the fin or taillight.

Now, second leak, passenger side floorboard rug was always wet, thought the hose connection was the issue, but while hosing the truck down we noticed there was drips coming in right-side kick panel in the corner. More swearing. Pulled the door side plate jam off to get some space in between the rugs to dry, was soaked. After Jimmy did some Jimmying, we pulled the wipers and the windshield cowling off, noticed there is an 4"x 8" access panel on the firewall metal ledge, passenger side. This was not sealed good, water came in around it, spilled into the cabin air filter inlet which was under the vent by a few inches, enough for water to get in, drip in truck, soak rug, etc. Pulled the plate, cleaned and caulked, plus put some of that flexseal super tape that the guy uses on the screen door to make a boat commercial. Put the hose to it, no more leaks. Sorry for the long explanation and forgot to take pics of this ordeal, but pretty straight forward if any leaks occur in your trucks. Pic below is the area where the access panel is below the cowling.