Water leak on passenger AND driver side

[dman102]

I live in florida where it rains pretty frequently. About a week ago I returned home from a drive to notice that the floorboards on in my car were wet and HOT. I shut off the car and didn’t end up driving it until a few days later, when it refused to start. I cleaned out the drains under the cowls (they were barley clogged) New battery in, the car is still refusing to start. Messed with it for a while, taking off the battery and putting it back on, and the car finally started up. I let it warm up then shut it off and came back to it today, where after a rainy night the floorboard has once again flooded and the car once again refuses to start.

the car acts like it’s possessed when I put the key in. The doors lock and unlock, gauges go crazy, CD player starts spinning cds around, etc.

I have determined that the issue is that the body control module is now bad due to the flooding. I am going to take it out and replace it, but I need to know where the leak is coming from!

everywhere I search says that it’s the drains beneath the passenger cowl, but that’s not the case, the drain is completely free and the water is still getting into the floorboards on the driver AND passenger side.

i am at my wits end here. Anyone else experienced this?

 

[86GT351]

When the drains get clogged, the water tends to roll to the passenger side and go into the vehicle through the cabin air filter area. that will cause the water to get to the BCM or Smart Junction Box.

 

[Dino Dino Bambino]

everywhere I search says that it’s the drains beneath the passenger cowl, but that’s not the case, the drain is completely free and the water is still getting into the floorboards on the driver AND passenger side.

i am at my wits end here. Anyone else experienced this?

Blocked cowl drains are the commonest cause of water intrusion into the cabin, but that only applies to the passenger side. If you're also getting water intrusion on the driver's side, the most likely reason is that the adhesive around the cowl cover retaining grommets has rotted and is allowing water to leak under the dash. Here's the fix:

 

[DieHarder]

Another likely entry point for water are the window seals which tend to perish over time and need to be replaced. Easy to do; just look up a few utube videos. You can buy 1" inch width x 1/8" inch thick foam tape weather seal at any major hardware store. If you buy the OEM version it's about $90 a side. Ridiculous cost for what it is. Up to you of course.

 

[Suecra]

Blocked cowl drains are the commonest cause of water intrusion into the cabin, but that only applies to the passenger side. If you're also getting water intrusion on the driver's side, the most likely reason is that the adhesive around the cowl cover retaining grommets has rotted and is allowing water to leak under the dash. Here's the fix:

This is the most likely cause, there is a ford replacement that you use a heatgun with to create a better seal to prevent this exact issue.

 

[ghunt81]

Probably the seals above the doors on the body, just like DieHarder said. I just had to replace mine although it seems like they are still leaking.

 

[Dimontague]

He said the water was hot

 

[Dino Dino Bambino]

He said the water was hot

Hot water can only enter the cabin from the heater core so if that's leaking, it's one hell of a faff to replace. The cabin would also smell of coolant.
You can band aid the problem temporarily by detaching the supply/return hoses and connecting them to each other in order to bypass the heater core altogether.

 

[VGMStudios]

You're getting your SJB wet. Which is the most likely reason why they car is acting like it's possessed. Take out the SJB and dry it off. I would also open it to make sure that there is no corrosion in there. You need to do more then clean out the clogged drains and waterproof the car.
Read this pdf. It will help.
https://drive.google.com/file/d/1QI-yYak90zmaMHGte5QN0ye-FYGzAUAP/view?usp=drivesdk

 

[DieHarder]

You're getting your SJB wet. Which is the most likely reason why they car is acting like it's possessed. Take out the SJB and dry it off. I would also open it to make sure that there is no corrosion in there. You need to do more then clean out the clogged drains and waterproof the car.
Read this pdf. It will help.
https://drive.google.com/file/d/1QI-yYak90zmaMHGte5QN0ye-FYGzAUAP/view?usp=drivesdk

This attachment... best resource to help you track down leaks. If up front most likely windshield grommets/doors /cowl drains. Regarding the water being hot is that due to leaking coolant or car is in a hot environment. If you're not losing coolant it's not from the heater core. I'd take the passenger seat out; take up the carpet and take it into a car wash. As you go thru check problem areas with a flash light. Should be apparent where it's coming from. In my case found both the windshield grommets and driver/passenger window seals needed to be replaced to take care of the leaks. They're actually easy fixes. Just a bitch determining exactly where it's coming from.

 

[massacre]

I know this is kind of an old thread, but just had this problem and wanted to thank VGM for the link to the procedures. My S197 has over 200k miles, original owner and my cowl drain was completely plugged. Pumped 1/2 gallon of water out of the cowl. Luckily the SJB seems good, i think i caught it early. Removed pass seat, under rug wet, floor wet. Everything is drying out now, waiting on new cowl grille seals hopefully that solves it.
Thanks again!

 

[VGMStudios]

I know this is kind of an old thread, but just had this problem and wanted to thank VGM for the link to the procedures. My S197 has over 200k miles, original owner and my cowl drain was completely plugged. Pumped 1/2 gallon of water out of the cowl. Luckily the SJB seems good, i think i caught it early. Removed pass seat, under rug wet, floor wet. Everything is drying out now, waiting on new cowl grille seals hopefully that solves it.
Thanks again!

You are most welcome! Glad to help. What I did with my cowl clips was take them out, add sealent from Home depot and put them back. Just as good and cheaper haha. Good luck with it though. Hope it will fix your issue.

 

[massacre]

You are most welcome! Glad to help. What I did with my cowl clips was take them out, add sealent from Home depot and put them back. Just as good and cheaper haha. Good luck with it though. Hope it will fix your issue.

I was thinking about doing that, but some of them are in pretty bad shape. My SJB doesn't look too bad, any tips on removing it?

 

[VGMStudios]

I was thinking about doing that, but some of them are in pretty bad shape. My SJB doesn't look too bad, any tips on removing it?

Ahh I see. As for the Sjb. Disconnect and remove the front connectors. Then there is one screw on the bottom. Then swing it up and out, disconnect the plugs on the back. If you are going to open it, take a picture of the fuses so you know where to put them back.

 

[massacre]

Thank you! Going to work on this later. Really appreciate all the help! I basically just want to dry it out. No corrosion that i can see yet but just worried about water in it

 

[massacre]

Got it out thanks for the heads up on the fuses. Couple drops of water but dried that up and leaving it to air dry for a few days. Appreciate the help

 

[massacre]

Was able to get the SJB back in today. Cleaned all of the pins with it apart. Pins looked good but not wanting to chance anything. Put the plastic covers back on, added dielectric grease to the pins. Blew out the connectors with air, then used quick drying electrical contact cleaner on them. Just trying to avoid moisture/corrosion in the future. Turned the key and nothing bad happened, hopefully everything is good.
Still have a fan blowing on the pass side carpet which has been removed from the floor. It's probably 90% dry at this point. I'll wire brush some light surface rust on the floor and add some rust encapsulator before i re-install the carpet. Once it's dry i plan on spraying the jute padding down with some water and bleach just to try and kill any mold that might try and form. The moisture in the car has made my cloth door inserts loose and they will need to be repaired.