Water leak into passenger's side A-pillar (2 Viewers)

[Jeffro Tull]

Gentlemen,

Long time listener, first time caller here. Thought it was high time I step out it into the light as the owner of an ’04 LX 470.

Also, I’m experiencing an infuriating water leak, and despite scouring the forum for insights and interventions, my latest water test has been just as dramatically unsuccessful as each previous one.

In a nutshell, I’ve got water penetration at the upper passenger side corner of my windshield that soaks through to the headliner where my A-pillar meets the roof liner. It would seem that water then flows down the interior of the A-pillar and eventually exits into the right side of the footwell. Like you can see, I’ve dismantled the glove box and trim pieces near the exit point of the leak and I can see where it’s indeed dripping out of the bottom of the A-pillar. Ominously, it drips through much of the wiring harness before eventually dripping onto the floor.

When I test with a hose, there’s no leakage until I run water within about half an inch of the actual top corner of the windshield. Even with copious water running down the windshield, so I know it’s not a lower drain or anything involving the rain tray.

I took this shot laying on the passenger side floor looking up toward the A-pillar.

On the advice in many of the threads addressing water leaks, I’ve applied silicone sealant all around the top right corner of the windshield. No worse, no better, so I can’t for the life of me figure out how it’s penetrating the A-pillar.

Insights?

PS - Pardon me if I've botched the acceptable process for posting pics!

 

[Trunk Monkey]

Search for sunroof drain leaks.

 

[Jeffro Tull]

I should have mentioned that I did that earlier. Water runs freely down both of the two drains at the front of the sunroof housing (if that makes sense) and exits behind the front tires. To my knowledge, these are the only two sunroof drains, no?

 

[deuce40s]

That is disheartening. I have the exact same leak, same spot. Yesterday I applied some flowable silicon to the top corner around the windshield mating surface and down into the body crack. I haven't checked to see if it's sealing yet though. The fact that yours isn't sealing is making me nervous. I'll drag out my water hose in a bit to test mine. Stay tuned

 

[hoser]

Remove trim around windshield (exterior/interior) and check the seal for water leaks.

 

[deuce40s]

My silicon attempt has failed as well. It's just as leaky as it has been. I'm at a loss. I've narrowed my leak to a 2 square inch area. I'll let mine dry for a while and add some more silicon I guess. Can't hurt.

 

[austintx]

I have the same leak in a 06 LX470... Just noticed it today.

 

[Jeffro Tull]

My silicon attempt has failed as well. It's just as leaky as it has been. I'm at a loss. I've narrowed my leak to a 2 square inch area. I'll let mine dry for a while and add some more silicon I guess. Can't hurt.

Likewise for me, which is a little bit baffling. I'd swear that I've thoroughly sealed every place in the area of the leak, but somehow water's still penetrating. Like you, I suppose I'll give it another go ... as soon as this torrential rain lets up.

 

[Jeffro Tull]

Remove trim around windshield (exterior/interior) and check the seal for water leaks.

When you say to remove the trim, do you mean just to probe the areas where rubber meets glass? Or are you suggesting a more invasive level of trim removal (i.e. actually peeling it away from the windshield)?

 

[deuce40s]

The rubber windshield trim just pulls right out. There may be a little bit of adhesive from the windshield installation though. I pulled mine back about two feet to get silicon in there. Then you can push it back in carefully with a tiny flat screw driver. I also pulled back the side moulding a little ways but I was afraid of bending it. My plan is to pull it back a little farther and squirt some more goo in it.

 

[TXLX100]

Has the windshield been replaced? If not, it's probably not leaking from there. I had a similar leak, it was from one of the front roof rack bolts.

 

[brosama]

Search for sunroof drain leaks.

Could a backed up sunroof drain cause a leak on the A-pillar even though he's pouring directly on the windshield in that specific spot (and not on the sunroof)? Does the windshield/A-pillar use the same drain?

 

[deuce40s]

Could a backed up sunroof drain cause a leak on the A-pillar even though he's pouring directly on the windshield in that specific spot (and not on the sunroof)? Does the windshield/A-pillar use the same drain?

No. There is a ~1/2" pvc line running directly from the sunroof, down the A-pillar, and out the bottom. The two can't mix unless there's a hole in the line, which is unlikely.

I finally found the source of my leak. The PO had the windshield replaced at some point and there was a tiny leak in the adhesive between the sun visor and rear view mirror. The leak would not drip straight down so it was tough to track with the head liner in the way. The water traveled across the length of the windshield to the corner, where it fell against the A-pillar. I put more silicon in the crack and so far it isn't leaking. The top windshield gasket does not fit as well as it did before since I added the silicon, so this is just a temporary fix until I can get a new windshield put in and sealed correctly.

 

[Jeffro Tull]

No. There is a ~1/2" pvc line running directly from the sunroof, down the A-pillar, and out the bottom. The two can't mix unless there's a hole in the line, which is unlikely.

I finally found the source of my leak. The PO had the windshield replaced at some point and there was a tiny leak in the adhesive between the sun visor and rear view mirror. The leak would not drip straight down so it was tough to track with the head liner in the way. The water traveled across the length of the windshield to the corner, where it fell against the A-pillar. I put more silicon in the crack and so far it isn't leaking. The top windshield gasket does not fit as well as it did before since I added the silicon, so this is just a temporary fix until I can get a new windshield put in and sealed correctly.

Thanks for this info, deuce40s. I'm going to try to replicate your fix today. Just to confirm - did you add silicone to the outside of the windshield (under the gasket), from the inside, or both?

 

[deuce40s]

Since you haven't exactly pinpointed your leak, start there. I pulled the gasket away and just used small amounts of water until I could feel where it was coming through the windshield. I gently poured water directly into the gap between the glass and the body, where the gasket sits. It doesn't take much water. Then I ran my finger behind the head liner from the dry side to the wet side to see where the water started.

I bought the flowable silicon and squirted it inside the glass and body gap, where I could see the windshield adhesive. This is below where the gasket sits. I couldn't tell if the leak was between the body and adhesive or between the windshield and adhesive, so I covered both bases and put a little extra silicon. I didn't put any silicon inside.