Water leaking into #4 sparkplug (what's the fix)?

[jseabolt]

2006 Explorer 4.6 liter, 131K miles:

This makes the second time this has happened. The first time this happened I replaced the #4 spark plug because I thought it was defective. Because when I did a tuneup about a year ago, the #2 Autolite sparkplug was bad straight out of the box.

A couple of months ago my Explorer developed a #4 missfire. When I replaced plug I noticed condensation in the boot. I did a taste test and confirmed it was not antifreeze. Yeah I know that is probably not the best way to identify a liquid but...

No missfires for awhile.

So it came a hard rain last week. The nose of the car was pointed uphill. The next day my Explorer developed a nasty missfire at idle. Eventually the check engine light came on. So I was going down the road and decided to "floor it" to see if this would clear it. Wishful thinking I guess.

So now then the check engine light starts flashing indicating a "really bad" misfire. After I slowed down the check engine light stopped flashing and then went off.

Got home, connected my code reader and just like before it's the #4 cylinder.

By the way, for those that don't know, #4 is the plug at the back of the engine on the passenger side.

Last time I installed a Motorcraft plug in the #4 cylinder since the new plugs I installed a few thousand miles ago were Autolites and I got a defective plug. They are probably the same plug, just rebranded.

So I called a buddy who is a mechanic at a Ford dealership and asked his opinion to see what might be the most likely cause, bad coil, bad injector or another bad sparkplug.

He told me what happens is rainwater leaks off the cowl and makes a straight shot into the #4 plug well. I told him that I noticed condensation when I replaced the plug the last time and wondered why it was there.

So the next day I pulled the coil/boot off the plug, sprayed some WD-40 into the boot and around the plug and blew it out with compressed air. Now the missfire is gone.

My buddy says to run a bead of silicone somewhere off the cowl panel and create a tail which directs rainwater away from the #4 sparkplug hole. But I cannot visualize what he is talking about. Anyone know about this "fix". Is this from a tech bulletin sent out by Ford or a fix him or a mechanic at his dealership came up with? I did not want to ask him.

I did discover two drain holes in the lip of cowl panel above the engine where water could possibly leak into the spark plug hole. There is actually four of them. Two in the middle and one on each end.

I took some alumnium tape and covered the center holes up that are in the middle from underneath. That way any water that collected in the lip would run toward the holes at the ends.

It came another hard rain a couple of days later. This time the nose was pointed downhill. So I would expect under this condition water would be more prone to leak but the next day there was no missfire. So I assume the plugging up the two drain holes in the cowl lip may have fixed the problem.

If this happens again, before I dry out the plug boot with WD-40, I'm going to open the hood and lay a water hose on the roof and flood the cowl panel to see if I can tell how water could be getting into the engine compartment. There is a rubber seal between the cowl and hood and it appears to be making a good seal. But may not be. I suppose I can always lay an extra piece of foam rubber under the hood to make a tighter seal.

Anybody have any experience with this same problem. How they fixed it?

 

[Flag Gibby]

Look for a post on water in the #8 plug well fix posted here sometime in the last 8 months I believe.

Found it here you go: http://www.explorerforum.com/forums/showthread.php?t=323026&highlight=Water+in+spark+plug

 

[jseabolt]

I suspected water might be leaking through the cowl panel clips. Another easy fix might be to just smear a gob of RTV around the clips where they protrude into the engine compartment.

I had a Fiat X 1/9 with a similiar problem. There cars were mid engined. The engine cover was slotted to allow heat to escape. One day I disturbed the wiring harness for the fuel injection. Everytime it rained, water would make a straight shot into the wiring harness and into the computer. I tried smearing RTV around where the harness branched off into other components but it did not good.

Luckily it was an analog Bosch L-jet system so I was able to dry it out with a hair dryer and reuse it so I kept a spare ECU on hand. Eventually I got tired of dealing with this issue and covered up the center section of the engine cover on the inside with a piece of sheet metal. End of story.

 

[GFish]

Wet #4 plug

My initial thought would be to apply dielectric grease inside the plug boots.

 

[swshawaii]

My initial thought would be to apply dielectric grease inside the plug boots.

Good idea and noted in the Ford Workshop Manual, although it does NOTHING for the water leak.

 

[jseabolt]

Good idea and noted in the Ford Workshop Manual, although it does NOTHING for the water leak.

I wonder if this is why spark plugs are bad about breaking off in modular engines? When I replaced the spark plugs, I sprayed the spark plug holes full of PB Blaster and let it sit for about an hour before I attempted to remove them. They were tight and required a short breaker bar but I managed to extract them with no issues. I applied some anti-seize compound to the new plugs just in case I keep this vehicle for years to come.

Dad's 2002 F-150 recently needed a plug change. I didn't have time to do it but the guy that replaced them somehow managed to remove them without breaking them off.

I'll try the dielectric grease. I would think any moisture would eventually dry out. However one thing that concerns me is the non-threaded portion of the spark plug past the threads showed signs of rust and was damp which makes me wonder if water is leaking past the threads and into the combustion chamber when it pools in the spark plug hole.

Believe me if you have never seen an engine try to compress water, it's not pretty. Here is what happened to my Fiat 1500 engine I was running in my Yugo turbo after I hit a large puddle of water from a clogged sewer drain which got sucked into the turbo:

http://s222.photobucket.com/user/tu...=2&page=0&_suid=13919906541410543518445446119

Notice how one of the pistons turned 90 degrees!

Dumbass me, was not running the splash shields and the engine ingested enough water which bent the connection rod and eventually broke. The engine didn't idle worth a damn afterwards but somehow managed to run OK until 2 months later I was pulling out from a red light and it threw a rod through engine block. I guess the bent connecting rod was causing a lower compression ratio in that cylinder.

Really made me mad. I only had 2000 miles on this $800 rebuild engine. Luckily it didn't seem to harm the valves so the head should be salvageable.

Hopefully covering up the two center drain holes with alumnium tape will fix the problem. If not my next plan of attack is to smear RTV over the cowl panel clips on the inside of the engine compartment.

 

[jseabolt]

I thought I'd give an update. Since applying alumnium tape under the center drain holes in the cowl we have had several hard rains, I have not had anymore issues with water draining into the #4 sparkplug. So I take it, that's the fix.

 

[Boomyal]

Did you have symptoms when water would get into the plug hole? I've been meaning to anchor a garden hose up on the windshield and let water run down, with the hood open. I'll be able to watch and see if any water drips through any of the clip holes.

I am not sure what the 'aluminum tape' is all about but I thought about putting a glob of Dum Dum over the hole and pushing the clip down thru it.

A few weeks ago I finally got around to giving my engine compartment and the underside of the hood a thorough degreasing and cleaning. I used Gunk Engine cleaner, then a scrub brush with soap and water, then flushed it all with the hose. I kept my compressor at hand to repeatedly blow any water out of the spark plug wells. Then I let it sit overnight before trying to start it. I still had a miss for several miles until everything heated up a dried out. I never did know where the miss was coming from.

 

[Spirithawk253]

I am having this same issue with my 06 Explorer, 4.6L V8... I just bought the car less than a month ago and water is getting in the coil/boot. My shop is having a very hard time of diagnosing where the water is coming from. I will present your post to them and see what they come up with. Once they tell me how they can fix it I will share!

 

[Boomyal]

I am having this same issue with my 06 Explorer, 4.6L V8... I just bought the car less than a month ago and water is getting in the coil/boot. My shop is having a very hard time of diagnosing where the water is coming from. I will present your post to them and see what they come up with. Once they tell me how they can fix it I will share!

Curious how many miles on your 2006 and what you had to give for it? I just bought a 2006 V8 LTD in mid December. It had 125k on it and I paid $8500 + tax and $800 to reseal both exhaust manifolds.

Other than a broken parking brake handle (which I fixed) and a burned out dash bulb, everything works. The interior is 98% and the paint is good. There are a few small warts on the body.

 

[Spirithawk253]

Curious how many miles on your 2006 and what you had to give for it? I just bought a 2006 V8 LTD in mid December. It had 125k on it and I paid $8500 + tax and $800 to reseal both exhaust manifolds.

Other than a broken parking brake handle (which I fixed) and a burned out dash bulb, everything works. The interior is 98% and the paint is good. There are a few small warts on the body.

I have 113,000 miles on my 06 and I paid $8999 no taxes. This was pretty comparable to the other cars that I saw with more miles and less options. My paint and body is good as well and I love the 3rd row seats. My other truck is a 96 suburban and I also have a 96 Impala SS. I decided to get an Explorer after having a ton of issues with my suburban. Hopefully after I work out the few minor issues I have found it will be a good car.

 

[Boomyal]

I have 113,000 miles on my 06 and I paid $8999 no taxes. This was pretty comparable to the other cars that I saw with more miles and less options. My paint and body is good as well and I love the 3rd row seats. My other truck is a 96 suburban and I also have a 96 Impala SS. I decided to get an Explorer after having a ton of issues with my suburban. Hopefully after I work out the few minor issues I have found it will be a good car.

Funny! I too have a Suburban. Mine is a '94 2500 454 with 44k miles on it. I couldn't afford to drive it anymore and it is so crude (although nice to drive) that I wanted to get rid off it before it is worth totally zero OR starts getting any expensive problems.

I bought the Expo to replace the Suburban and a '91 Toyota Previa van. I wanted one vehicle that would carry a few people, get around in the snow, be able to pull my mid-weight 20 ft boat and get something better than 8-9 mpg. Also I got tired of licensing, insuring, buying tires, brakes and batteries for two vehicles when I put very few miles on any of them.

So far, since December, the Explorer has been stellar. I am averaging 15.5 mpg in mixed driving and nothing has broken. I did have to replace a dashlight bulb and do an ingenious repair to the parking brake release handle but other than that, EVERYTHING works.

As I do not know what the spark plug history is, I have amassed a new set, an extraction tool and the nickle anti-seize compound. I have also been running Techron in the gas. When we get another good run of weather, I will endeavor to pull the plugs and see what they look like. So far, no indication that they are finished, but then I do not have a record as to when they were last changed.

 

[Johnmike]

2006 Explorer 4.6 liter, 131K miles:

This makes the second time this has happened. The first time this happened I replaced the #4 spark plug because I thought it was defective. Because when I did a tuneup about a year ago, the #2 Autolite sparkplug was bad straight out of the box.

A couple of months ago my Explorer developed a #4 missfire. When I replaced plug I noticed condensation in the boot. I did a taste test and confirmed it was not antifreeze. Yeah I know that is probably not the best way to identify a liquid but...

No missfires for awhile.

So it came a hard rain last week. The nose of the car was pointed uphill. The next day my Explorer developed a nasty missfire at idle. Eventually the check engine light came on. So I was going down the road and decided to "floor it" to see if this would clear it. Wishful thinking I guess.

So now then the check engine light starts flashing indicating a "really bad" misfire. After I slowed down the check engine light stopped flashing and then went off.

Got home, connected my code reader and just like before it's the #4 cylinder.

By the way, for those that don't know, #4 is the plug at the back of the engine on the passenger side.

Last time I installed a Motorcraft plug in the #4 cylinder since the new plugs I installed a few thousand miles ago were Autolites and I got a defective plug. They are probably the same plug, just rebranded.

So I called a buddy who is a mechanic at a Ford dealership and asked his opinion to see what might be the most likely cause, bad coil, bad injector or another bad sparkplug.

He told me what happens is rainwater leaks off the cowl and makes a straight shot into the #4 plug well. I told him that I noticed condensation when I replaced the plug the last time and wondered why it was there.

So the next day I pulled the coil/boot off the plug, sprayed some WD-40 into the boot and around the plug and blew it out with compressed air. Now the missfire is gone.

My buddy says to run a bead of silicone somewhere off the cowl panel and create a tail which directs rainwater away from the #4 sparkplug hole. But I cannot visualize what he is talking about. Anyone know about this "fix". Is this from a tech bulletin sent out by Ford or a fix him or a mechanic at his dealership came up with? I did not want to ask him.

I did discover two drain holes in the lip of cowl panel above the engine where water could possibly leak into the spark plug hole. There is actually four of them. Two in the middle and one on each end.

I took some alumnium tape and covered the center holes up that are in the middle from underneath. That way any water that collected in the lip would run toward the holes at the ends.

It came another hard rain a couple of days later. This time the nose was pointed downhill. So I would expect under this condition water would be more prone to leak but the next day there was no missfire. So I assume the plugging up the two drain holes in the cowl lip may have fixed the problem.

If this happens again, before I dry out the plug boot with WD-40, I'm going to open the hood and lay a water hose on the roof and flood the cowl panel to see if I can tell how water could be getting into the engine compartment. There is a rubber seal between the cowl and hood and it appears to be making a good seal. But may not be. I suppose I can always lay an extra piece of foam rubber under the hood to make a tighter seal.

Anybody have any experience with this same problem. How they fixed it?

I know it’s been a while but I’ve had a problem with water in #7 on a 4.6 in an F150 but because it’s my go to the dump vehicle have lived with it. I ran into a post where they talked about a leak from the cowling but other than a 1/4 in gap in the sheet metal lip that holds the weatherstrip that seals to the hood didn’t see anything that looked like a problem. With the history of intake manifold issues it looked like I was in for a goose chase. Anyway after cleaning the pine needles out of the channel behind the weatherstrip it took less than a pint of water in the channel to have full flow through that 1/4 inch gap right over #7. Have not sealed it off yet but have no doubt that it is the problem and can see how any defect, rust hole, broken weatherstrip, plugged weep holes if there are any,could dump water on the engine. I believe my problem was exasperated because it was an infrequent driver and even then not enough to get good and hot. Pouring a little water behind the weatherstrip is an easy check. Make sure the vehicle is parked in its normal at rest inclination.

 

[ng07exglenn]

I just wanted to add a few things since I just ran into this water in both rear coils/cylinders . I have found that 2 of my cowl clips on the driver side to allow water in and also my windshield washer nozzle ports allow water in. Weird thing is the nozzles aren’t broken but the gaskest at the base are. I’ve been chasing a p2135 code associated with actually one of the coils that’s been fouled and now I noticed how instantly my explorer runs like crap after the 2 big rains in my area this year since I bought it back in August.

Awaiting another windshield nozzle, napa only had on I’m town sadly, and i tried pulling the cowl but it’s glued down to the windsheild. So it I poppped then loose and tried pressing the sponge down for now. Will figure out another appoach to that, need a new windsheild anyways but it needs to wait till next year.

Nick