P2 passenger footwell leak solution with photos

[volvolugnut]

The problem: Occasionally I would find the floor mat wet on the passenger front footwell of 2001 V70. Initially I checked the carpet under the rubber mat and found the carpet felt dry. I made the wrong assumption that the rubber mat was catching the drip as it fell from somewhere under the dash.
Later I read posts here and learned that the carpet has a thick foam pad and the carpet itself would not generally feel wet when you feel the top. However, the foam pad underneath can be soaked.
Other posts talk about plugged sun roof drains that cause leaks to driver and passenger side footwells.
Look here viewtopic.php?f=9&t=71407&p=473882&hili ... an#p473882
for posts on checking the sun roof drains for plugging and leaks. When I checked my sunroof drain tubes, they were ok and drained to the ground.

I searched deeper into the problem to try to find the source of the water. Look here: viewtopic.php?f=9&t=79080&p=425794&hili ... et#p425794 to see how to remove the front carpet. Note the comment to try not removing the sill plates. I missed that note and had to get new attachment clips.
I found my front passenger side carpet was wet in one area. See photo of removed passenger front carpet and pad.
Back side of the carpet showing the foam pad.

The back passenger carpet pad was not wet.

I looked under the passenger side dash and found the two tubes for water drains. One is from the blower motor housing and the other is for the cabin air filter. They both tee together and then go to outside drain.

Moving on to other potential leak points, I removed the cowl cover . See viewtopic.php?f=9&t=76919&p=410806&hili ... ve#p410792 for instructions to remove the cowl cover. With the cowl cover removed, I found dirt and trash in both corners. See photo of debris. The red circle indicates the drain fitting. The plastic drain fitting has 4 drain holes flush with the metal floor of the cowl.

I poured water into the drain holes at the front edge and confirmed water runs to the ground and not into the cabin. I cleaned out the debris on both sides. Then I poured water into the drains on both sides to confirm they drain to the ground. I confirmed that the cabin floor was not getting wet.

I replaced the cowl cover and poured water on the windshield above the cowl cover while checking the cabin for water. I had noted the seal at the bottom of the windshield to the top edge of the cowl cover did not look to be water tight. It is a hard plastic Z shape with aluminum internal stiffener. It did not have any adhesive or rubber material that would stop water from flowing around the edge and into the cowl blower inlet. Perhaps it originally had adhesive, but my windshield has been replaced. After several quarts of water poured on the windshield I found a small trickle of water into the cabin. The water was coming from somewhere behind the blower that I could not see. I removed the cowl cover and confirmed there was water inside the blower housing.

I puzzled over how water was getting behind the blower housing if the cowl drain and the blower housing drains were clear. I checked inside the air inlet duct with a mirror. There was a crumbling foam seal above the blower housing and below the cowl.
This was likely the way water was getting to behind the blower housing. I removed the air inlet duct and confirmed there is a raised metal lip that prevents water from the cowl floor getting into the blower housing unless water level gets about 0.5 inch deep. With the cowl drains clean this should never happen. If you want to remove the air inlet duct, there are six clips on the duct. Carefully pry the clips inward and lift the duct up from the bottom of the cowl.

I was fairly sure the foam seal was causing the leak and decided a cover for the air inlet duct would solve the problem. In fact, there are posts that describe a cover used on later Volvos to prevent this leak into the blower housing. I decided to make my own rain deflecting cover. Since I have metal forming experience and not plastic forming experience, I chose aluminum sheet to make my rain cover.

First step was taking some basic measurements to find the cover dimensions. Then I made a rough cardboard shape in the size needed and taped the corners where the cardboard folded. It fit ok, but needed to be deeper to assure the drops on the rear, left corner ran forward and off the front edge. A second, more refined cardboard model was made. See photo of cardboard model outside of cowl.

See photo of model inside the cowl.

This model looked good. Next step was to make the aluminum cover. I used 0.063 thickness aluminum sheet (purchased from Summit Racing online). See photo of pattern layout on aluminum sheet.

After cutting out the aluminum shape it looked like this.


I bent the sheet by clamping over a steel plate edge and using a hammer. Not good enough for public view, but it worked. Here is the completed cover out of car.

Bonus points if you identify my photo table. Cover installed in cowl opening.

I tested the cover with a couple gallons of water on the windshield. Worked good so far. No water inside the cabin on the floor. It will rain in a few days for the real test.

Rain came and still the cabin floor is dry. I used four dabs of Goop Marine adhesive (one on each corner) to hold the cover in place.
See photo.
.

If you want to make your own cover, here is a photo of the cardboard pattern with dimensions.

Reply to this post if you have questions.

volvolugnut