Water leak in the roof

JimCost2014 · February 25, 2016

update on my fine truck. being told it is the weather strip (gasket/seal) on the sunroof glass. truck has been at the dealership since 02/20/2016. this thing has been in for repairs so much, that I have actually made a full months payment without even having the vehicle in my possession. paying for a 56,000.00 truck and driving loaners for 30 plus days. wonder what the future holds, if I ever get it back.

JGAVER46 · February 27, 2016

JGAVER46

Update. Service manager got back to me and informed me that a GM service bulletin had been issued for the repair of the ONSTAR antenna. Truck will go into GM dealership Monday the 29th. Service manager says the ONSTAR antenna is back ordered!. Offered a loaner sedan.

Not a happy camper!!!

JGAVER46 · February 27, 2016

JGAVER46

Update. Service manager got back to me and informed me that a GM service bulletin had been issued for the repair of the ONSTAR antenna. Truck will go into GM dealership Monday the 29th. Service manager says the ONSTAR antenna is back ordered!. Offered a loaner sedan.

Not a happy camper!!!

COP TZR · March 30, 2016

Have a call going into dealer tomorrow at 7am. Thanks for posting this..

Just remembered I most recently in the past couple months got an update done for 4G or something for the OnStar. Anyone know if this update required any replacement, removal, or modification to the roof antenna?

update: dealer says the 4G update was internal and nothing to do with roof antenna

COP TZR · April 8, 2016

Have a call going into dealer tomorrow at 7am. Thanks for posting this..

Just remembered I most recently in the past couple months got an update done for 4G or something for the OnStar. Anyone know if this update required any replacement, removal, or modification to the roof antenna?

update: dealer says the 4G update was internal and nothing to do with roof antenna

They replaced entire antenna assembly as they said they could not order just a replacement seal. Fine with me. In/out of shop same day. Waiting for the spring rainy season.

BuddyS · July 31, 2016

All, see below for the issue with the 2014 and some 2015 antennas. The antennas on some 2015 and 2016 are slightly larger. Since the water gets trapped under the antenna I was always thinking it was breaking through the secondary foam gasket. I had replaced this antenna about a year ago. Well yesterday I was getting drips from the sun visor area again. I pulled the antenna and was going to add some sealant under it. Instead I noticed water coming out of the wire hole. This told me water is getting into the antenna itself which I always thought could happen because the water never was ever to escape when it got through the vent hole in the rear. What a crappy design. GM does know this can happen but I still do not see an updated design for us. This will eventually happen to almost all antennas and will fail. I put a new one one and was going to make a slit in the front but wasn't to keen with that so I placed a small amount a butyl tape to clog the hole and keep the water out. I did this with the first one that was on the truck when brand new but figured I would be OK when I replaced it with a new one. It doesn't seem like GM is going to update the design and I didn't really what to use RTV so that's why used the butyl.

Dnt · September 22, 2016

Never even thought of an issue such as this, that is the danger of reading these dang forums. I just looked at my onstar antenna thing and see a slot left at the back where IT looks like water could get in. Pic attached surely to goodness that is not happening IS IT?

pm26 · September 22, 2016

Never even thought of an issue such as this, that is the danger of reading these dang forums. I just looked at my onstar antenna thing and see a slot left at the back where IT looks like water could get in. Pic attached surely to goodness that is not happening IS IT?

onstar antenna.JPG

If you look at this design closely, there is a secondary gasket around the hole in the roof which should keep the water out. The slot in the outer gasket allows some water to seep under the antenna up to the inner waterproof seal. The slot also allows for evaporation of moisture on a hot day if there is any water trapped inside the outer seal. For those having water leaks the obvious problem is that the inner seal does not seal adequately. There is a nut on the inside that needs to be tightened sufficiently to compress the inner seal. I suspect lousy workmanship is to blame here as it appears that some nuts are probably left finger tight from the factory. Unfortunately, you need to pull down the headliner to access the antenna nut. I would attack this first.

So in summary, the inner seal is what keeps the water out, and outer seal with the slot is just a dust seal.

BuddyS · September 23, 2016

Yes and any heat within the antenna from the electronics themselves and the sun getting it hot will cause a vacuum to draw the water in that is stuck under it. This is what I assume was happening to me since the primary seal wasn't leaking. I was getting water leaking from the cable egress hole.

SierraMyst · October 6, 2016

So it poured rain here in for three days straight. I didn't drive at all during those three days.

The forth day was warm (75) and pretty pretty humid due to all the rain. Went to get in the truck late afternoon and there was moisture on all the inside windows.

I couldn't see any stains on the headliner, no wet carpets, no visible water intrusion.

The only thing that seemed odd was that there was a faint white film on the inside of the back sliding window. It appeared to be soap from the high pressure touch less cash was so use. Odd that it would be on the inside. More odd that I hadn't washed the truck in over a week, so why was this showing up now, I don't know.

But all the moisture on the windows due to the heat and humidity has be a sign of water intrusion.

The back slider has quite a bit of up/ down play in it and some minor left/right play. Is that normal?

Is this moisture normal or do I have a bigger problem and need to take it in before the winter snow and rain?

Joe Perry · October 28, 2016

I've got the exact same problem (and photo) as the initial post. I was told the drain line was missing. What gives? Does anyone at GM actually know what the problem is?

pm26 · October 29, 2016

I've got the exact same problem (and photo) as the initial post. I was told the drain line was missing. What gives? Does anyone at GM actually know what the problem is?

Drain line? I do not think there is any drain line on the antenna. On sunroof opening, if your truck has one, yes.

dlang13 · November 9, 2016

Got in my truck last night after work and on my way home water started leaking from one side of the drivers sun-visor. I think it came in from the back part of the roof because it didn't start dripping on me until I started going downhill. Has anybody else had this issue. I don't have a sunroof.

Had this issue in my 2011. Water leaking from the interior lights, they said it was the shark fin then it was the brake light....

they never did fix it, my radio started shorting out and electoral doing finny things so i traded it off.

Bought a 2015 Now and have other problems...Good luck with GM Customer Service they are probably one of the worst people to deal with. Once they have your money they do nothing for you (us)!!

Good Luck!

Pacfanweb · November 12, 2016

2015 Sierra SLT with sunroof here. Just noticed a few drops coming in from the top of the windshield in front of the sun visor on the passenger's side the other day after a hard rain. Planning on making an appointment with the dealer tomorrow. Hope it's a simple fix.

Interestingly enough, my 1998 SLT Z71 leaked around the back window when it was less than a year old. The dealer ended up replacing the entire glass which fixed the problem. Sadly, though, I'm just now getting a leak around the top of the windshield on the driver's side of that truck. Have leaks in both "professional grade" trucks now... :-(

Still have not lost faith in GM, although reading some of these posts is quite alarming.

Thanks,

Ken

I wouldn't read that much into it. Remember, it's mostly the folks who have problems that post. The hundreds of thousands that don't leak aren't posting to tell us theirs is fine.

It's a numbers game. The vast majority are fine.

Pacfanweb · November 12, 2016

I've got the exact same problem (and photo) as the initial post. I was told the drain line was missing. What gives? Does anyone at GM actually know what the problem is?

If the sunroof drain is missing or clogged, you can have the exact same symptoms.