Leaky cowl causing misfire?

[Kiwifrog]

Hi All,

First up, so appreciative of this forum and the wealth of experience behind it! Thank you!

I have an issue with rough idle that I’m almost certain is as a result of my cowl leaking water into the 4 and 8 coil & plug wells of my 2002 Explorer v8 Limited. At first I thought maybe the manifold was leaking, but remembered back to a previous thread where I had a plug blow out (successfully repaired with insert) during which member X-LION pointed out water was in the plug well of my photo…

Help identifying a part for engine repair - Blown Spark Plug

Very thankful for that post before I started down the track of manifold! Anyways, this is what it looks like below. You can see water wash across both the top and down the back of the engine cover that directly line up with the cowl plugs. Cylinder 4 plug and coil were replaced which resolved the problem for a few weeks till another bout of heavy rain and rough idle returned.

Some questions to help out a novice please before I fix the leak and redo the coils…

1. Can I simply silicone the cowl plugs and if so what kind should I use?

2. Is it only the 4 cowl plugs rectangled in red I need to silicone? If so can the water then travel else where and cause other problems? Where does it outlet if the cowl plugs are sealed?

3. Are there any places other than the cowl that could be leaking water into the plug wells. Noting that cylinder 3 was the one full of water on the old thread, so cowl water can travel that far? It had been outside in rainy weather for several months prior to that photo in the old thread. I don’t think the manifold is the issue though, the reservoir level hasn’t dropped and too much points to the cowl.

4. Am I missing anything else?

Many thanks in advance!

The photos...

Plug 4 has been replaced. This is plug 8 with the endo camera - not done yet nor the coil but rust gives it away. Well wasn't full but wet on end of the coil when I removed it. I think this may be the one making it run rough now.

 

[mountaineer2004]

This is a very poor design on Ford's part...shame on their engineering department.

I had the exact same problem as you and solved it by siliconing all the red square areas.

My engine shield is missing (who knows where it went) ... I'm surprised you're still getting the problem with the engine shield in place.

I'll send pics later, but you know the idea.

 

[warnerwh]

I also filled mine with silicon after seeing something on this site. When putting in new plugs when blowing out my number 8 plugs a ton of rust came out but I didn't realize where it was coming from. I agree with the above that Ford's engineers did nothing to fix this problem. Mine is an 05 so they knew about this problem for years and did nothing.

 

[mountaineer2004]

 

[mountaineer2004]

Hi All,

First up, so appreciative of this forum and the wealth of experience behind it! Thank you!

I have an issue with rough idle that I’m almost certain is as a result of my cowl leaking water into the 4 and 8 coil & plug wells of my 2002 Explorer v8 Limited.




Some questions to help out a novice please before I fix the leak and redo the coils…

1. Can I simply silicone the cowl plugs and if so what kind should I use? yes ... use good quality silicone

2. Is it only the 4 cowl plugs rectangled in red I need to silicone? yes If so can the water then travel else where and cause other problems? no Where does it outlet if the cowl plugs are sealed? somewhere else

3. Are there any places other than the cowl that could be leaking water into the plug wells. no Noting that cylinder 3 was the one full of water on the old thread, so cowl water can travel that far? It had been outside in rainy weather for several months prior to that photo in the old thread. I don’t think the manifold is the issue though, the reservoir level hasn’t dropped and too much points to the cowl.

4. Am I missing anything else? don't think so, as it worked well for me

 

[Kiwifrog]

@mountaineer2004

Thanks for those shots and replys to questions. Super helpful!

With the engine cover, it lips down at the back but the lower edge sits pretty much directly over the top of the 4 and 8 coils. Then combining that with the fact that the cowl holes are located that when leaking, the engine cover acts as funnel to send the water straight down onto the top of the coils! If you look at the second engine cover shot in my first post above, you can see the darker areas where the cowl water stream has left it's mark down the back of the cover - onto the coils! Somebody at Ford screwed up for sure!!

With my last thread where the cylinder 3 plug blew, I did have the engine cover off (bonnet down) for several months during that winter before the repair which probably didnt help. And the winter rain is hard and persistent here with global changes. So I think that's how the water made those back 2 cylinders worse and also further forward to the 3rd cylinder. It's the most logical reason. Before the plug repair I turned it over to blow out the water and there was a LOT in there including what was in the cylinder (no plug in at that time) - more than a manifold leak could produce. Rain!

Anyways I'll plug those holes and replace the coils and plugs where needed and see what happens.

Thanks again for help and advice!

 

[mountaineer2004]

@mountaineer2004

Thanks for those shots and replys to questions. Super helpful!

With the engine cover, it lips down at the back but the lower edge sits pretty much directly over the top of the 4 and 8 coils. Then combining that with the fact that the cowl holes are located that when leaking, the engine cover acts as funnel to send the water straight down onto the top of the coils! If you look at the second engine cover shot in my first post above, you can see the darker areas where the cowl water stream has left it's mark down the back of the cover - onto the coils! Somebody at Ford screwed up for sure!!

With my last thread where the cylinder 3 plug blew, I did have the engine cover off (bonnet down) for several months during that winter before the repair which probably didnt help. And the winter rain is hard and persistent here with global changes. So I think that's how the water made those back 2 cylinders worse and also further forward to the 3rd cylinder. It's the most logical reason. Before the plug repair I turned it over to blow out the water and there was a LOT in there including what was in the cylinder (no plug in at that time) - more than a manifold leak could produce. Rain!

Anyways I'll plug those holes and replace the coils and plugs where needed and see what happens.

Thanks again for help and advice!

My pleasure...

Also wanted to mention that if you plug up those 4 holes with silicone, the water will simply travel to the outer edges and safely disappear to the ground...I tested where the water went the day after (with a garden hose) and it worked perfectly.

so plug those leaky holes from ford's terrible design and I'm sure all will be well. Good luck!

 

[Kiwifrog]

My pleasure...

Also wanted to mention that if you plug up those 4 holes with silicone, the water will simply travel to the outer edges and safely disappear to the ground...I tested where the water went the day after (with a garden hose) and it worked perfectly.

so plug those leaky holes from ford's terrible design and I'm sure all will be well. Good luck!

OK, thank you!

Some more novice questions if I can ask for advice please.

A mechanic replaced the plug and coil on cylinder 4. I was quite keen to try doing cylinder 8 myself as I already have the parts. Can the plug be installed without needing to remove the fuel injector rail and is that capacity the same for all cylinders? I see the air intake tube on bank 1 side would need to come off too if doing all plugs/coils. Would anything else need removing?

I will also need to get tools. What length extension would you suggest for down the plug hole. I can pick up a torque wrench for a reasonable price. Was thinking a 3/8" (arm is about 16", torque starts at 18.5 Lbf⋅ft). I have a plug socket that fits that size already.

Not being too adventerous?

 

[mountaineer2004]

OK, thank you!

Some more novice questions if I can ask for advice please.

A mechanic replaced the plug and coil on cylinder 4. I was quite keen to try doing cylinder 8 myself as I already have the parts. Can the plug be installed without needing to remove the fuel injector rail and is that capacity the same for all cylinders? I see the air intake tube on bank 1 side would need to come off too if doing all plugs/coils. Would anything else need removing?

I will also need to get tools. What length extension would you suggest for down the plug hole. I can pick up a torque wrench for a reasonable price. Was thinking a 3/8" (arm is about 16", torque starts at 18.5 Lbf⋅ft). I have a plug socket that fits that size already.

Not being too adventerous?

I changed my plugs several times and don't remember any real obstacles. A 9" extension would work.

Tekton makes good torque wrenches. I torqued them to 20 foot-pounds for the spark plugs.

Life should be an adventure...enjoy fixing your vehicle.

 

[mountaineer2004]

One more thing, get a spark plug socket that securely and snugly fits the plugs (with foam or whatever that is inside the socket)

The spark plug wells are deep and there's no need to mess around with cheap sockets where the plug is falling out, either when lifting it out, or bringing them to and down the well.

 

[Kiwifrog]

One more thing, get a spark plug socket that securely and snugly fits the plugs (with foam or whatever that is inside the socket)

The spark plug wells are deep and there's no need to mess around with cheap sockets where the plug is falling out, either when lifting it out, or bringing them to and down the well.

ok, perfect timing!! Just this evening I was checking my socket against plug and thought exactly that - then checked back at the thread and exact same thought! I think they’re available with a rubber grip or magnetic maybe - will test with a 5/8 plug in store.

One additional cowl leak area I discovered too. I can’t see this setup on your Mountaineer but my Explorer has these pipe holders rectangled just below the cowl plugs that when I water tested my repair were also leaking (I had dismounted the pipe temporarily). Only a few minutes with the garden hose on ‘shower’ on the cowl and drip, drip, drip in the engine bay - same area. So anybody with an Explorer will need to seal those too.

 

[mountaineer2004]

ok, perfect timing!! Just this evening I was checking my socket against plug and thought exactly that - then checked back at the thread and exact same thought! I think they’re available with a rubber grip or magnetic maybe - will test with a 5/8 plug in store.

One additional cowl leak area I discovered too. I can’t see this setup on your Mountaineer but my Explorer has these pipe holders rectangled just below the cowl plugs that when I water tested my repair were also leaking (I had dismounted the pipe temporarily). Only a few minutes with the garden hose on ‘shower’ on the cowl and drip, drip, drip in the engine bay - same area. So anybody with an Explorer will need to seal those too.

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What were Ford engineers thinking? Silicone everything lol !