smashweights
Well-Known Member
Well I may have found the culprit. Allow me to walk you through just in case anyone else encounters this problem. First I had to remove the wiper cowl. I used this video to figure it out. Pretty easy other than the wipers were on pretty snug.
Under the cowl you'll find the wiper motor and a large cavity. The driver side and passenger side each have 3 drain holes. Both were completely clogged with debris. The cabin air intake is on the passenger side and has a nice upward scoop. My guess is if these drains are clogged up enough rainwater will pool in the cavity and then when the truck is in motion it splashes up into the cabin air intake and is sucked into the filter and fan.
The driver side was rather easy to access. I used a shop vac and a long appliance brush to clean out the drains.
The passenger side is a bit harder. There's a heat shield looking piece that I think is just to block water running through the cowl grate getting directly into the cabin air intake. On second glance, looking at the side view it might not actually impact the cabin air intake? I still wouldn't remove it just in case.
Basically had to lie on top of the engine and blindly work the brush until it hit the holes then check to see that each one was cleared. Needed a shop vac extension to get under there. But they both cleared out nicely.
Replaced everything with ease. Word to the wise: don't over torque the wipers, if you're slightly off on the alignment they'll be hell to get back off to tweak. Better yet, test the wiper movement before you tighten down the nuts. Hopefully this fixes the issue. Water now drains out around the wheel wells when I tested it with the hose. Bit of debris came out too. Biggest downside is I can't see any way to do this without taking the cowl off if it recurs...
Total time about 30 minutes. Could be a 15-20min job easily though. I could see this also causing a wet dash or floorboard if the caulking at a few spots allows water to get through if it pools high enough. Basically if you have any water ingress issues in the dash during or after a rainstorm I would check these out.
Under the cowl you'll find the wiper motor and a large cavity. The driver side and passenger side each have 3 drain holes. Both were completely clogged with debris. The cabin air intake is on the passenger side and has a nice upward scoop. My guess is if these drains are clogged up enough rainwater will pool in the cavity and then when the truck is in motion it splashes up into the cabin air intake and is sucked into the filter and fan.
The driver side was rather easy to access. I used a shop vac and a long appliance brush to clean out the drains.
The passenger side is a bit harder. There's a heat shield looking piece that I think is just to block water running through the cowl grate getting directly into the cabin air intake. On second glance, looking at the side view it might not actually impact the cabin air intake? I still wouldn't remove it just in case.
Basically had to lie on top of the engine and blindly work the brush until it hit the holes then check to see that each one was cleared. Needed a shop vac extension to get under there. But they both cleared out nicely.
Replaced everything with ease. Word to the wise: don't over torque the wipers, if you're slightly off on the alignment they'll be hell to get back off to tweak. Better yet, test the wiper movement before you tighten down the nuts. Hopefully this fixes the issue. Water now drains out around the wheel wells when I tested it with the hose. Bit of debris came out too. Biggest downside is I can't see any way to do this without taking the cowl off if it recurs...
Total time about 30 minutes. Could be a 15-20min job easily though. I could see this also causing a wet dash or floorboard if the caulking at a few spots allows water to get through if it pools high enough. Basically if you have any water ingress issues in the dash during or after a rainstorm I would check these out.
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Nice write up. Thanks! Seems weird to me to have the drains on the side like that.
