So after months of trying to figure out how water is coming into the passenger area in my Mustang, and after reading HUNDREDS of posts on this and other forums, I dedicated today to fixing this ****ing problem. I thought it might take all day, but I figured it out pretty quick.

I left this morning for some breakfast, and since we had hard rain last night I knew I'd see some leaking... not as much as I got (probably 40 - 50 ounces, and yes, I am serious). So I got out the towel I carry with me, soaked it all up, wrang it out, soaked it up, wrang it out (you get the idea). So I get back home, rip off my cowl, and start taking pictures to see what it might be. I was pretty shocked to see a pool of ****ing water where the cabin air filter goes (see pictures below).

I got all the water out (just soaked it up with rag) and looked down there and saw this grommet looking thing totally caked up with gunk. I pulled it out and saw there was a slit at the bottom, so apparently it WAS designed to drain water, but since the slit it so small, and so much **** got backed up into it, it was making the water back up. And as you see, my cabin filter is ****ing disgusting now, so I have to order another one of those.

I hope this helps anyone that is having this problem. Hopefully we can all enjoy dry floorboards now!!!




Dried out now with some towels

Crap/Gunk in grommet

Location of grommet

Note the sludge in the grass that came out of the grommet


And of course I need a new cabin air filter now

Now she's all clear to drain!

 

let us know if this fixes it!

 

Keep us informed.

 

I studied my own cowl panel and investigated how in the world leaves would be able to get in like that. The actual cowl intake vents are set high completely under the rear edge of the hood while at the base of the windshield there is a dam that is recessed and directs the water out the ends of the cowl panel to the insides of the fenders so they drain somewhere in the wheel well outside of the engine compartment. The flexible rubber seal against the bottom of the windshield isn't all that tight. I suppose leaves can slide under the rubber and work their way in, especially with the help of forced air intake from the blower motor.

Where the wiper pivots come through there is just enough room for small leaves and gunk to slip through the pivot openings.

I suppose not parking where leaves can collect from trees may help, but you may be better off leaving the grommets off to yield a larger hole. Other than that I would periodically inspect this area if you are consistantly parking under or near trees.

I am sure when Ford designed the cowl on some CAD system they did not do a real world test to see what would happen if leaves get trapped in and around the cowl panel. It may be easy to route just rain water by itself but it doesn't seem like they took into consideration what would happen if you parked under a tree.

You would think after over 100 years of building cars they could get something like this right the first time.

 

I have trees all over my property, and they line my driveway, and sadly, I have no garage, so at the moment I have to continue parking there. My plan was to change the cabin air filter twice a year, and while doing so, clean out any crap that may fill the hole. I am leaving the grommet off as I see no reason why it would benefit me to keep it on.

 

This reminds me of the issue I had on my old '68 El Camino. Back then it was a big selling point to say your car had 'flush and dry' rocker panels. The idea was that any debris caught at the base of the cowl would be blown down and out of the front fenders by wind coming into the cowl. The reality of it was that leaves and debris would get stuck at the bottom of the front fenders, clog the drain holes, and cause rust. That's why many old muscle cars from all makes and models have rusty front fenders at the bottom, in addition to rust from road salt, etc.

Its been an issue since at least the 60's, and still is today. I tend to be pretty **** about leaves down in the cowl for that very reason. Ford isn't going to spend the time testing how debris collects in the cowl, they probably have bigger issues when designing a car. Its not right, but just reality.

 

I'm sure this is gonna help a lot of people..Good find.Thanks for the info

 

I agree it is a very poor design...I am constantly removing small bits of debris from the cowl area in hopes of it not getting in and clogging the drains. Last time I replaced my cabin air filter I really didn't look straight down to see if any debris was collecting. I'll be sure to do that the next time I replace that filter (real PITA to change that cabin air filter...another poor design feature, just an afterthought by Ford).

 

Huh??? I think it took me about two minutes to replace mine. The problem is where the air plenum has to be located. There just isn't any better place for it.

My brother recently changed the cabin air filters on his Suburban. It took him over two hours to get the job done. I'll take two minutes over two hours any day!

 

good catch..my only thought about leaving the grommit off is make sure the metal isn't bare anywhere and if it is just hit it with some silicone or paint to seal it up. Just to help cut down on any possible rust issues down the road.

 

Yep took me about two min also.

 

Good find. Sadly this reminds me of the cowl issue that plagued the 1st gen Mustangs. debris would plug the drainholes and water would builld and eventually rust out the cowl hats. The only was to repair it correctly was to split the cowl (drilling 130 spot welds) replace the lower cowl with a repo piece or cut and splice new hats in. Then you still had to spot weld 130 holes and refinish the panel. At least 45 years later the panels are primered but unfortunately still an issue.

I would cut the bottom off the grommet so it is bigger and allowed more stuff to fall through.

 

That is one thing that amazes me. Ford should do a more complete job of painting the vehicle-there are numerous spots that just have the green primer (inner fenders where the door jamb is, underbody, cowl) My last vehicle was a Chevy Colorado (had major issues) but it at least had a good paint job, both the underbody, cowl, and inner fenders were all painted. I could not find any primer visible on the truck at all. Yeah it might cost more but the car will probably last longer, especially for owners who live in the rust belt.

 

Actually, this is not just a Ford problem!!! I had some massive puddles in the front passenger side of my Mercedes C class and come to find out, a drain tube in the vent cowl had gotten clogged and the water overflowed through the cabin air filter...oh wait, that's the exact same Sh## that happened to you!!

So the moral of the story is check your drain holes.

-Darth

 

I had the same problem. After cleaning the drain, no problems since.

 

Thank you for adding this information, but, it will fall on deaf ears here; the text you have typed will become invisible to all , because according to everyone, any problem any Ford (except for European designed Fords of course) has is due to sh***y incompetent Ford design, no matter that other more prestigious manufacturers have products with the same problem.

I've had leaves clog the cowl drains on my Mopar A-bodies and in my 240Z as well.

 

Definitely a good find. Will have to check on mine, as well. From the pics, the hole is straight down from where the cabin air filter is?

 

aside from the water, did you get any funny smells with the AC on?

 

I had same trouble on my 05 so trade it on a 08 GT.

 

It's down and more towards the center of the car. It's the only grommet in that area, so you shouldn't miss it.