Truck Head Scratcher

[TOXIC]

My 2016 Silverado High Country has developed a strange water leak.  Started after a couple hard rains and I noticed water in the Weathertech floor mat on the drivers side. It was a small puddle in the middle.  I had driven it in the rain so I just thought it came in on my shoes and there was no sign of any dripping from under the dash.  I ran my hand all over under there and no water.  I dried it out and reminded myself to keep an eye on it.  It happened again in the next rain but then again, I had driven it so I doubted myself.  Was out at my daughters farm yesterday and it rained last night.  I made sure to look at the mat when I got home.  Went out this morning and there was a small wet spot on the mat.  Once again, no trail or wet spot under the dash I can find.  Funny thing is, I have noticed my windshield has been fogging up on the inside some where it has never done that in the past and it seems like I am hearing more wind noise than normal.  It’s been raining all day and supposed to rain tomorrow so I’ll see if the puddle grows.  In my research I have found the following possibilities:

 

Cowl drains plugged

Shark Fin antenna seal bad

AC drain plugged (ruled out because it only does it in the rain)

Sunroof drains plugged

3rd brake light seal

Wimdshield seal

 

i don’t think it’s the 3rd brake light since all of those I’ve seen leak show up on the headliner.  Same with the Shark fin antenna.  My headliner has no moisture.  When the rain stops, I’m going to take the hose and start at the cowl drain lines and bottom of windshield wet it down and see if it leaks after a good amount of time.  If no leak then it’s up to the Shark fin, if no leak, it’s to the sunroof and finally the 3rd brake light.  Hopefully it will show itself. 

[A-Jay]

Just a total guess but I'm picking windshield seal.

Good Luck

A-Jay

 

[Jigfishn10]

Along @A-Jay’s diagnosis and the fact that it’s fogging up on the wind shield, do you hear whistling while driving? 

[VolFan]

I had a similar issue, but with a different vehicle - a 2006 4Runner. It was the sunroof drain clogged with pollen and a poplar seed. Putting weedeater twine through it and then some warm soapy water syringed through fixed it.

 
Just a little water would run through the drivers side pillar and drip on the floor Matt. Drove me nuts because I’d feel a little splash on my leg but couldn’t figure out where it came from.

[TOXIC]

@VolFan That would be a good resolution.  I don’t cherish trying to seal the shark fin, windshield or 3rd brake light.  
 

@Jigfishn10 I thought that as well but if the water travels to the floorboard anywhere behind the dash, it could fog the windshield.  I’m trying to objectively examine if I hear more wind noise or if I’m just paying more attention. 😂😜

[casts_by_fly]

We had similar on my wife’s car ages ago. Same as volfan but different vehicle yet. Sunroof drain backed up with gunk. Hope that’s your problem. Easy fix. 

[Jigfishn10]

13 hours ago, TOXIC said:

@Jigfishn10 I thought that as well but if the water travels to the floorboard anywhere behind the dash, it could fog the windshield.  I’m trying to objectively examine if I hear more wind noise or if I’m just paying more attention. 😂😜

Hahaha 

If the air leak is at the top of the windshield then water could roll off the roof, into the roof/windshield intersection and could wick back into the headliner. It then builds up and drips as the case with my son’s car. But it sounds like you’ve may have ruled that out and I don’t have a visual of the location of water on the on the floor board. Sorry I wasn’t a help here   

[TOXIC]

4 hours ago, Jigfishn10 said:

Hahaha 

If the air leak is at the top of the windshield then water could roll off the roof, into the roof/windshield intersection and could wick back into the headliner. It then builds up and drips as the case with my son’s car. But it sounds like you’ve may have ruled that out and I don’t have a visual of the location of water on the on the floor board. Sorry I wasn’t a help here   

That’s the odd thing.  It’s right smack in the middle of the weathertech, almost squarely under the steering column but nothing is wet around or under the column.  It rained all last night and of course it’s dry, no puddle today. 😜

[detroit1]

Somebody is messin' with you.

[VolFan]

Drive it a little and see if it starts dripping, that is when mine was most noticeable.

[TOXIC]

Well, I’m not going to get too many 60 degree days this time of year so I decided to get the hose out and run water directly on every spot that is prone to leak.  Started with the cowl drains.  Water drained so fast it created a whirlpool.  Sprayed both sides and middle.  Waited long enough for the water to make it into the cab if it was going to.  It didn’t.  Moved up to the shark fin antenna.  Let water run on it for 5 minutes, then waited another 5 to see if it made it to the cab…nope. Moved on to the sunroof.  Same deal.  No water intrusion.  Same with the 3rd brake light.  So…..I got some hot soapy water and poured it down all of the drains on the truck.  Hopefully that cures it.  Due to the nice weather I went ahead and washed the truck and put 303 Aerospace Protectant on all of the rubber seals. Finished up early afternoon so I thought….what the heck….and pulled out the wax and did my final wax of the season.  Included the rims and chrome.  Dang thing better not leak now. 😂😜

[A-Jay]

It might still leak but it will look pretty dang good while it does it. 

Good Luck

A-Jay

[12poundbass]

No leak that you can find. Puddle in the middle of the floor mat. This will keep your leak from running down your leg to your floor mat. You’re welcome!

 

[TnRiver46]

I’ve seen some trucks leak up under the glove compartment onto the floor mat, usually air conditioner sweat I think 

[gim]

1 hour ago, 12poundbass said:

No leak that you can find. Puddle in the middle of the floor mat. This will keep your leak from running down your leg to your floor mat. You’re welcome!

 

Is that @J Francho on the front of the package?!

[J Francho]

That doesn't look anything like me. 
 

[A-Jay]

1 hour ago, gim said:

Is that @J Francho on the front of the package?!

No - That's Me !

I poop my pants all the time.

Don't You ?

#lumpynickers

😎

A-Jay