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Rainwater leak from cowl to carpet

JoCat

NAXJA Member # 1584
NAXJA Member
Location
Southern CA
Like many, I've recently noticed wet carpet on both the front driver and passenger sides, although most often on the passenger side. Footrest areas seemed dry, as was the headliner and under the door trim. Baby powder all over stays dry always. I looked in the cowl as best I could (long flashlight and mirror - this is a 2001 4.0L XJ w/ AC and California emissions) and I didn't see any debris. I pulled the HVAC drain hose and it is clear, and I ran a pipe cleaner 6" up the plastic fitting and felt no resistance. My compressor is on loan, so I couldn't try blowing air. I removed the passenger seat and side trim and pulled the carpet back on the passenger side. It was wet all right, but no rust yet so I've got this early on.

As a test yesterday I dumped a large pitcher of water into the cowl on the driver (open) side. The result was unexpected, and now I need a lesson in jeep anatomy. Most of the water poured into the cowl came running out the weep holes in the bottom of both front doors. The driver's door was closed, and the passenger door was open - it made no difference. Engine compartment firewall stayed dry, and water coming out the door is below the threshold for the inside of the jeep. That isn't the source of the wet carpet. First question - how is the water getting from the cowl to the door? I would prefer to think it isn't passing through the flexible rubber boot covering the electrical wiring, but I fear I will be disappointed.

A much smaller, but still appreciable, leak came dripping out from under the passenger side dash. I removed the glove compartment to have a better look. Water was coming from the seam between the upper and lower halves of the HVAC case, on the front right corner and on the right side as far forward as I could see. I noticed the flange of the case was cracked where the screw joins the two halves, and that may be part of the problem. The screw may have been overtightened. I had the heater core replaced about two years ago by a dealer, and they should have used new gaskets as well as seen any cracks, but who knows.

Second question - is a pipe cleaner long enough to establish that the HVAC vent is completely clear, or could there be a block higher up? I didn't see any water coming out that drain when I flooded the cowl, although I'll have to try that again to be sure. Related question - is that drain exclusively for air conditioning condensate, or should I even expect cowl rainwater to drain there first?

I would guess a normal rain would never dump as much water into the cowl as quickly as I did. Final question - do you think rain would ever likely fill the HVAC case as high as the seam and/or the channel to the door? I wonder if I created a pathological condition and thus missed the real leak.

Rained all day today, so nothing further done. Any thought on the various openings and their relative heights above the cowl floor appreciated.

Thanks in advance.
 
Subscribed. We just found water on the passenger floorpan after 4-5 days sitting outside (it's usually garaged). I have not had time to investigate yet, but need to do so before reinstalling her carpet (in the middle of an interior swap).

Craig
 
Also consider that many high mileage XJ's, may have some rust holes on the leading edge of the bottom floor panel zone where it meets the angle of the engine's area, (exterior), firewall, and along the upper areas of the transmission tunnel. Really requires further close inspections in order to disregard splashing road puddle intrusions.
 
Common areas for water leakage are: the firewall seals around the HVAC components, windshield seal, capillary action at the firewall seams, leaks at the am/fm antenna grommet, door seals, misaligned or drooping doors not sealing, floor pan/wheel well rust holes.

The HVAC drain tube is for condensate.
 
This type of water leak seems to be a common problem on later model XJ's...here's what I did to fix it on my '98.

The first culprit I suspected was the plastic air intake that located under the windshield cowl. You have to remove your wipers, and remove the cowl cover. The intake is underneath some sheetmetal, that obviously prevents water from pouring straight in. I cut the sheet metal away just above the intake. Once I had a hole large enough for my hand to fit in, I simply applied some sealant around the plastic cowl intake, where the foam seal is to seal it off. I then used some plastic sheet to make a "patch" over the hole I cut in the sheet metal. Seal it up with silicon, and you'll be fine.

Unfortunately, this wasn't the cause of my leak, but it was good preventative maintenance since I figured the foam seal around the cowl intake won't hold up over time much longer.

This led me to then next possible area for leak, and that one being the foam seal where the blower pokes through the firewall on the passenger side. Pop your hood an take a look at where I mean.....that is an easier fix. You might have to move some piece of emmissions equipment that sort of blocks your access to the foam sealed area, but its only a couple of bolts, and you can lay it aside. Once you have clear access to the blower seal, just apply some silicon all around where the blower meets the fire wall to seal it up, and seal up the foam really well.

Also, there is a wire loom that runs along the fire wall above the blower, that splits off towards the fender, and then runs down towards the engine. In my case, water was dripping off that wire loom and dripping straight into the blower area. That was the source of my leak. Take a look at yours, I bet it's doing the same thing. Just zip tie that wire loom aside, so that it no longer overhangs above the blower.

I haven't had a leak since...
 
Many thanks for the suggestions, but I had already seen the usual causes. The leak happens when the jeep is parked, so road splash can't be responsible. As I said the floor is sound, as seen both from above and below. Antenna lead isn't involved when I just pour water into the cowl, unless it routes through the cowl somehow.

Access to the blower motor seems problematic. The metal accumulator lines aren't flexible, and I could only slide it up and down a small amount. On a side note, anyone know the size of the screw that holds the accumulator holding band in place? The captive nut is there, but the screw is missing. The leak detection pump is right over the blower hole, and there is something else I don't recognize below that. Moving the accumulator means discharging the A/C. I might be able to disconnect the LDP, but I don't really hold out much hope of reaching the blower without A/C service. I really miss the days when I could identify the parts on a car. Anything over 40 mph in my old CJ2A was exciting, but then anything could be fixed with a screwdriver, a crescent wrench, and a BFH. But I digress...

Cutting open the cowl on the passenger side is certainly possible, but once the intake to the HVAC box is sealed where would the water go next? My leak doesn't seem to be running down the outside of the HVAC box from the cowl area, but rather from water entering the box through the air intake, filling the box, and then spilling out a crack in the seam between the upper and lower halves of the HVAC box. If that's true, I would think the evaporator drain must be plugged because that should have drained first, but didn't. However, there is no obstruction within 6 inches of the outlet (pipe cleaner length), and I would guess that's enough to rule out a blocked drain. Maybe I'm not picturing the inside of the HVAC box or cowl correctly though. Perhaps the bottom of the box isn't flat inside. In any case, if the HVAC rain is only intended for condensate then where is rainwater in the cowl supposed to go?

I saw a picture of an intake splash shield/baffle (http://www.naxja.org/forum/showthread.php?t=1076439&highlight=cowl+leak) that would seem to indicate the baffle acts like a kind of snorkel, with the air intake an inch or more above the floor of the cowl. I'm sure I didn't pour in enough water to fill the cowl an inch deep. In that case maybe the water is coming in around the outside of the shield (where the foam gasket sits) and drips down the front of the HVAC box, where I can't see it, then around the side to the front right corner and down. Maybe the shield goes in pointing down instead of up and the snorkel analogy is wrong. Maybe the shield doesn't even exist in the 2001 model year, as I can't find the PN (55037128AB) in my 2001 parts catalog. Also I didn't see a shield when I tried to look inside the cowl. Online searches say it is discontinued, so I don't see any picture of how it is fitted, but it only shows up for the 2.5L engine. If water isn't intended to enter the blower intake, and thus isn't intended to drain from inside the HVAC box (because it isn't normally intended to get in there), and it isn't intended to run through the rubber boot to the doors alongside electrical wiring - then how is it supposed to drain out from the cowl? I'm obviously confused...

I was actually wondering if anyone knew what the openings in the cowl were. Obviously the rain (and air) intake at the top on the driver's side, and an opening I can't see into the top of the HVAC box for fresh air into the cabin. Clearly some way to get to the doors also, but I don't just where those are (I can't look at it just now as I covered the jeep over to keep out the rain yesterday and I'm waiting for a little dryer weather this week).

Maybe there should be a drain hole in the side of the cowl (same idea as cowl intake, but smaller) with a hose to take the water down towards the bottom of the engine. If there were a baffle on the passenger side of the drain hole it would keep water from ever getting to the HVAC intake unless the drain's capacity was exceeded. Of course, water would just sit on the driver side unless the drain could be placed as a low point. Actually, water will just sit there now unless the floor of the cowl slopes down to the air intake (or wherever it is supposed to drain to), so that might not be any different. On second thought, any hole in the side will have a lip between it and the floor which will retain water. The cowl could use a drain on the bottom. Any way to get there?

Cheers.
 
The cowl area is nothing more than a covered rain gutter, with the airbox intake duct poking up thru it about an inch or so. Any water that enters the cowl area, runs off towards the fenders and drains from there.

The openings in the fender area where the water drains are fairly big, so it would take a butt load of debris, such as leaves or pine needles to plug them up. And you would have to plug up both sides before you could stop water enough to then divert into the intake duct.

The air intake in the cowl area is located directly beneath the sheet metal, about center of the windshield wiper stalks. The sheet metal is there to prevent rain from pouring in directly. A removable louvered trim covers this sheet metal area.

That is why in searching for my cabin leak, I cut out a section of the sheet metal away; so that I could get my hand in there to apply silicone around the air intake duct. I then used some plastic sheet to cover the hole, replaced the louvered trim and called it a day...

The other emissions part I referred to earlier is the fuel system purge valve on my '98. Just removed a few bracket bolts, unhooked some hose, and move it aside; so I could access the blower motor areas. Yours may be different.
 
Thank you - that sounds like just what I'm looking for. I think the intake may have changed a little in 2001 though, or else I'm missing that one inch extension above the cowl floor. How does the drain into the fender feed into the doors though? Even with a door open water poured out all 3 or 4 drain holes at the base of both doors. That's certainly where the large majority of the water drains for me. In any case, I think your suggestion to just open up the passenger side cowl and seal around the air intake is an excellent one. That way too I should be able to actually see where the water drains.

Thanks again...
 
I think I finally have my leaks (five so far) identified, so it seems a good time for an wrap-up

The first leak was the cowl air intake, and I approached it using the write-up at http://liftedtrucksusa.com/forum/cherokee-grand-comanche/1074-jeep-cheokee-xj-water-leak-fix.html. Once caveat - a nibbler won't cut out the entire piece. There is a slide in the way, and I used a dremel with a cutoff disk across that. Instead of cutting out a large contoured patch from a junkyard donor, I fashioned one from some aluminum sheet and a ball peen hammer. The original slide proved too big to refit back in on the underside of the new patch, so I made a new one out of aluminum and a few pop rivets plus some 3M strip caulk. After the repair water poured into the cowl no longer dripped from the HVAC box. Thinking job well done I sprayed the hood/windshield with a garden hose. Well, the floor still got wet - just not from the HVAC box.

Second leak was from the blower motor opening. Fleet service manual (FSM) says to discharge the A/C and remove the accumulator, but others have said you can reach down there by moving the leak detection pump (LDP). The FSM says to remove the LDP you remove the filter on top, disconnect one electrical connector (pull the orange clip up using pliers - the orange color is so you can find it again after you use a pick to pull it up and out), and a few hoses (OK so far), then unscrew two screws holding the pump the to its bracket. This just goes to show you the people who write these manuals really do have a sense of humor. The screws are under the bracket and way in. I tried three different offset screwdrivers and gave up. Anyway, to get that blower out you really need to remove both the accumulator and the LDP, so I took it to a real mechanic. LDP took him about one minute. In case anyone else needs to do this you should remove the bracket instead. I tried that myself, but failed. The two top bolts are easy, but it hung up on a third underneath an electrical bundle running to the power distribution center (PDC) that I was afraid of lifting. The secret is that the bottom of the bracket has a slot in it and not a hole. Lift the wire just enough to unscrew the bolt a little, then slip the bracket out. Easy, when you know how. He was able to seal all around the HVAC to firewall opening, and put a thin layer of sealant around the blower motor to HVAC box opening by removing and reinstalling the motor. BTW if you test the motor (and you should) before putting back the LDP be prepared to clear the malfunction indicator light when all is done. The non-functional LDP will set a code.

Now both water into the cowl and a hose test result in a dry floorboard. Well done again. Put everything back, vacuumed up the baby powder, and went to do the same on the driver's side. Oops, the driver's side floor is soggy. Water into the cowl doesn't get it wet, but an outside hose test does.

Leak three: There is a gasket on the rear edge of the hood which seals the hood to the cowl. Mine looked good, but I applied a long strip of weather stripping (Frost King 3/4-in x 10-ft Black Foam Door Weatherstrip, $3.48 at Lowes) on top and that helped, but it wasn't enough.

Leak four: I sealed holes in the pinch seam on the driver's side (see the second picture in http://www.naxja.org/forum/showthread.php?t=1073190&highlight=water+leak). This requires moving the large wiring harness, which for me always breaks off the fir tree push prongs on the zip tie. I tried using some ties from NAPA (PN 770-9346), but I can't recommend them. They have two large, thick prongs that are hard to push in when the cable is attached, and break off inside the cowl when you try to remove them. I'm going to see if I can get a few OEM style ties (either http://www.waytekwire.com/item/21372/FIR-TREE-MOUNT-50-LBS/ or http://www.waytekwire.com/item/21374/FIR-TREE-MOUNT-50-LBS/. I don't know how thick the cowl wall is, so I don't know which will work best.

Anyway, during a retest I could still feel water getting in around the main wire bundle coming through the firewall above the driver's left foot (where C101 would be, if a 2001 had that connector - see left side of the first picture in the same thread).

Leak five: After removing the kick plate I could see the large rubber grommet was both cockeyed and sliced up, and I had a broken wire. I managed to crimp on a splice with butt connectors, and now there's a little light on the dash that tells me when my hand brake is applied. Who knew? Anyway, it looks like whoever cut it up installing ARB locker wiring really hacked up that rubber seal. I sealed up the inside of the opening and about 3/4th of the outside with strip caulk. The lower left section on the engine side is difficult to reach without removing the brake booster.

Retested with a hose for five minutes, and everything stayed dry on both sides. I'll have to wait for a proper rain to be sure, but in southern CA we're in a drought and no rain is in sight. Time will tell. The moral of this story: when it rains, it pours - everywhere.
 
Thanks for the update.., some never do.., anyway some of us inquiring minds want to know.., as the future of XJ problems are easier to deal with, with solutions provided to this, (our), shared site.

I for one usually check this site out before checking my e-mails daily, as my XJ DD battles it's way through some of the worst paved, and back road conditions I've ever experienced in Ca., Or., Wa., Nv., Ut., Wy., Ne., S.Da., Pa., N.y., Fl., La., and a few others in-between said. Local mechanics here are generally great, but there are so many different vehicles existing, so many different pieces, parts, and functions, and such time delays in obtaining parts, (since our dear leader had that 'cash for clunkers' program that effectively had most XJ's in my area removed), that it is a good thing to at least make a hobby out of learning as much, being as familiar as much as possible with present, and future possible problems with the XJ. So, a hearty thanks for your update hombre.

Had to change out a H4 bulb, within CIBIE glass in 30-40 mph windy sleet, in the dark-time three days ago.., took me 18 minutes. Night before, had a starter ground wire become loose from ice/snow debris continually battering it, and now an issue with the rod connection working the ignition switch. With the friendly resolutions found here at NAXJA, I have been able to maintain my XJ in more-or-less, (lol) tip top condition. Thanks everybody.., and happy new year.
 
Still trying to track down my leak(s) on my 98 sport which only occur when raining or with a hose test. So far after reading numerous posts about this, I've sealed every rubber grommet on the passenger side firewall. Sealed the blower motor from the engine side. Sealed the Antenna cable where it passes thru to the interior. Cut an opening thru the cowl and sealed around the fresh air intake with plumbers putty and rtv on top of that (both should remain pliable for a long time). Had a new windshield installed. The installer said he found no rust. Not sure what to do next. Trying to not have to remove the dash but I may have no choice. On the plus side after removing the interior to clean and dry I had a chance to clean the floor pans (the rust was minimal and only surface rust) primed it and put a coat of bed liner down. Interior is reinstalled and just the passenger corner carpet is pulled back. Anything I've missed in terms of stopping the leak would be greatly appreciated. I guess I should mention that the leak drips down from behind the glove box from somewhere above the heater/blower box.
 
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You didn't mention the pinch seam that runs all the way across the front of the cowl area on the engine side (second picture in http://www.naxja.org/forum/showthread.php?t=1073190&highlight=water+leak). I sealed mine on both sides, after cleaning with brake clean and some wipes - also some openings up along the outside edges. Then there is the OEM rubber gasket running all along the forward edge of the cowl, which is easy to get to. It wouldn't be hard to change that, but mine looked to be in good shape so I just added weather stripping on top of it to ensure a tight fit. When the hood closes the seal is compressed, and I'm confident that section is water tight. When those are done - which is far easier than what you've already done - someone suggested using a hose to water the firewall directly, starting at the bottom and slowly working your way up until you find the leaky area. I didn't do that as I don't think the firewall is actually intended to get that wet, but if you use a slow flow that might be a good way to narrow down the area. Another easy test is just to pour a pitcher of water into the cowl opening in the driver's side. That way you can test the seal around the air intake in relative isolation.

The only opening I've read about that leaks onto the HVAC box is the blower motor opening, which you've already sealed. There are two areas to seal around the motor, and I expect you got them both. The main leaky area seems to be the seal between the HVAC box and the firewall, which is the outer ring where you can see/feel the foam gasket for the HVAC. The second is the surface of the HVAC box the blower motor screws onto. That isn't sealed originally, and it's further into the opening. The only way to seal that is to pull the motor and put a little sealant around the rim of the blower before reassembly. Don't use too much - you may need to get the motor back out someday. It shouldn't get wet, but I had mine sealed just in case.

It can take quite a while to find these leaks. I would only test one area a day, so that everything was dry between tests. Otherwise I was never sure if a leak was just slow to penetrate, and a prior test was responsible for any water seen inside. The only thing I can suggest is to pull the glove box, test an area with a pitcher or hose, and watch to see when it leaks. Best of luck.
 
Thanks. I'll try to seal those as soon as the weather warms a bit. It's supposed to be in the teens tonight and single digits tomorrow night and barely above freezing during the rest of the week. I've been looking for the leak and taking small measures for over a month now so what's a couple more days.
 
I had a real bad leak in my 97 when i got it that would drip down by my left foot i could see it come thru the dash and bottom of windshield but no where else. I checked all the wiring harness stuff because it seemed like when water hit it, it would run inside thru the grommet. electric taped it like crazy/ added a new grommet and still had the leak. Paid to have my windshield replaced, that didnt do it. Fixed small rust spot on roof, no luck. took all the roof rack bolts out and filled the holes with "the right stuff" liquid gasket and ended up fixing my problem. Not sure if that will help u at all but i didnt see that mentioned, might of missed it tho. Good luck hopefully u can fix it before u have to drill holes in the floor to drain it haha
 
I don't have a roof rack, so I'm at least spared that one leak source. Window is a possibility, but I actually think I've managed to get all my leaks stopped. It passes a hose test, and I'm just waiting for actual rain to be the final test. Southern California is in drought, but I'm hoping for some rain sometime this year. Only a negligible amount forecast for the next month, but meteorologists have, on occasion, been known to be wrong. Cheers, and thanks for the assistance.
 
Leaking heater core could also make you have wet floorboard on passenger side right? I think mine is leaking a little.
 
Certainly, but it wouldn't be rainwater. You can tell coolant, and it would only be on the passenger side. I had the heater core replaced when it leaked a couple of years ago by a dealer, which is when some other problems came up. If you do replace the heater (or pull the HVAC box for any reason), I'd recommend replacing the gasket (or at least sealing) around the air intake in the cowl, new gasket kit for the firewall, and a new metal blend door. Hard place to get to, so might as well do it all when you're in there. I don't know if it's cause or coincidence, but it's always felt like the heat was partially on since the heater core was replaced. The blend door motor and control is fine, and the door swings easily, but I only recently found the late model doors can flex causing a leak. HeaterTreater makes a replacement door that can be installed after cutting a hole in the side of the box. Pricy but the dash stays in place, and if you need to replace the heater anyway ...
 
I agree 100 percent, if I was to replace the core I would be doing any and everything I could while inside there...I'm going to bypass mine though, being a toy vehicle vs a DD I'm okay with losing heat (and defrost :bawl:)

I'm fairly certain my water issue is not rain water. As you said, its only on passenger side, it feels like coolant, and there is a very, very, slow loss of coolant. Also, I think my core is clogged, I have essentially zero heat.

Good luck with your repairs.
 
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