Leak, passenger side windshield. (1 Viewer)

[coffee]

Well gang, I am officially a member of the leak club.
I spent some time with the hose today, I was able to rule out all other spots. The leak only happens when the water hits the lower passenger A pillar as shown in photo.
Drips to the left side of passenger floor mat, significantly if heavy rains. I guess I will have to pull the cowl and take a look. Searched some previous posts regarding leaks and apparently if it’s not the sunroof drains, it can be pretty daunting to diagnose.

 

[bloc]

Search for cowl cover. The water is most likely coming in via the fresh air vent at the base of the windshield and through the cabin filter and blower motor. If you remove the inspection hatch for your cabin filter you may find it wet in there.. and if you don't know don't move the recirc flap manually.. use the fresh/recirc button as part of your HVAC.

There was also another 200 with a manufacturing defect where water in the cowl area could flow in through a strange hole in the body, that wasn't intended to be there. I'm having trouble finding that thread.

There are lots on the cowl issue though.

 

[coffee]

thank you bloc

 

[ryanCA]

Yeah the cowl issue is hugely problematic on the 200 and has been for a long time.

Do you have original glass, or has it been replaced?

We get 8 days of rain a year here. However, on one of my wife's 200 lease, it got a glass repair at a Lexus dealer (I know they sub it out), and when I washed the car few months later, whole interior was wet. They did a horrendous job. Given lease was ending, it wasn't a big deal, but I know that has happened to some people as well.

Keep us posted

 

[bloc]

Found the thread with the manufacturing defect.

Wet driver floor, AC drains?

Can you get a box fan in there to move some air? I did a little vornado near the desecant packs to try to get some flow . That said even before the fan after baking for a few hours, it felt extremely dry. I'm hoping this will just be the polish for anything I can't feel or see. Damprid is...

forum.ih8mud.com

I will say this is very unlikely though. I've been around here for years and that's the only one I know of.

 

[coffee]

Ok, I got the cowl off, pretty straightforward.
I was hoping for an aha moment, but I don’t see anything that strikes me as a leak. This fresh air box area is completely dry as is the foam gasket surrounding it.
The foam gaskets on the cowl are all dry, dusty and pliable too. I am tempted to take the side plastic windshield trim off, but the white clips don’t seem to want to cooperate.

 

[coffee]

It looks like the windshield may have been replaced at some point prior, I don’t see a Toyota logo.

 

[coffee]

I thought I would update this thread for others that may have these symptoms in the future.
I visited the glass place this morning and we were able to remove the side windshield trim on the A pillar, interior and exterior. The sealant looked neat and professionally installed, with no evidence of any leaks. Hoze, the glass man, was 99.9% sure it was not the glass or a failed or sloppy sealant.

The interesting thing was with the cowl removed we were unable to replicate the leak. We filled the entire firewall gutter and the water just flowed out the drivers side and passenger side, we covered the fresh air intake with tape and were careful not to spray in it. We even sprayed down the A pillar and into the fender/ firewall areas thinking maybe it was a factory defect or lack of seam sealer.
No leak.

We then removed the tape from the fresh air intake and reinstalled the cowl. After about two minutes it started to leak again just like in my first post.

We deduced that water is getting under the cowl and running along the underside and dropping down into the fresh air intake. Probably off to the side as the plastic cowl has an integral gutter right above the fresh air area.

I read in another post that someone replaced the foam on the cowl seal with some success. I bought a very similar size and type of weatherstripping foam from Lowes and changed out the primary foam seal. After removing the original, I cleaned with alcohol and cotton ball, then used the smallest bead of gorilla glue before pressing the new seal on.

The secondary seal and little butt seals I dressed with dielectric grease. Not so much as to make a mess, just a little to soften them.

Success. The leak is gone.
Here are some pictures of the seal.
Also note, the original cowl seal, on top, is open foam, my replacement, on bottom, is closed cell.

 

[bloc]

Good tech, thanks for following up.

Reading about all the cowl leaks has had me really curious but so far after two windshield jobs mine hasn't started.. Your observation that the water may be running along the bottom is plausible. Especially because some people have said if the vehicle is pointed nose up or down (can't remember which) on a hill it gets much worse.

 

[coleAK]

I would almost guarantee you need a new cowl. I’ve had this same leak and every time what ultimately fixes it is a cowl. I’ve done the weather stripping but for me it didn’t last.

 

[coleAK]

Good tech, thanks for following up.

Reading about all the cowl leaks has had me really curious but so far after two windshield jobs mine hasn't started.. Your observation that the water may be running along the bottom is plausible. Especially because some people have said if the vehicle is pointed nose up or down (can't remember which) on a hill it gets much worse.

For mine nose down was worse.

 

[bloc]

I would almost guarantee you need a new cowl. I’ve had this same leak and every time what ultimately fixes it is a cowl. I’ve done the weather stripping but for me it didn’t last.

What was the substantive difference with a new cowl vs changing the weather stripping on yours? Maybe the tightness of the fit into the slot at the base of the windshield?

Not doubting your experience, just trying to wrap my head around the root cause without taking mine apart.

 

[coleAK]

What was the substantive difference with a new cowl vs changing the weather stripping on yours? Maybe the tightness of the fit into the slot at the base of the windshield?

Not doubting your experience, just trying to wrap my head around the root cause without taking mine apart.

What I’ve found is that it isn’t the weather stripping that fails on the cowl it is the plastic clip sections on the cowl that fail. When those clips don’t fit in as tight it is only a matter of time before water intrudes. I’ve also replaced the stripping, what I found there is every time I take the cowl off and on to do that the clips get worse.

I’m at the point where when I need a new windshield again I’ll take the cowl off and install it myself. That way I can be super careful and know right away if the clips are loose or damaged. I’ve also accepted that a windshield replacement is mostly going to need a cowl replacement as well.

I’ll also add for me the leaks have been worst when we get warm wet heavy snow. My thought is that the snow just sits in place and soaks with a lot of water volume. That said we never get heavy rain like can occur in warmer climates.

 

[bloc]

What I’ve found is that it isn’t the weather stripping that fails on the cowl it is the plastic clip sections on the cowl that fail.

Thanks for the detail.

 

[coleAK]

Thanks for the detail.

You’re welcome. If you take the cowl off it is the the plastic clips that are super fragile. The ones on the bottom side of the cowl that fit into the engine bay firewall slots (one pictured).

 

[LX Cruiser]

What I’ve found is that it isn’t the weather stripping that fails on the cowl it is the plastic clip sections on the cowl that fail. When those clips don’t fit in as tight it is only a matter of time before water intrudes. I’ve also replaced the stripping, what I found there is every time I take the cowl off and on to do that the clips get worse.

I wonder if thicker weather stripping puts more pressure on those clips, too.