4th Gen 4.6 V-8 Spark Plug Questions

[Steven G Webb]

Attempting to solve the rumble strip, engine surge problem I decided to tackle the spark plug replacement yesterday afternoon. Couldn't find a 9/16 spark plug socket (thanks again Ford) so had to go with a deep socket and use a magnet to retrieve the plugs. Ran a can of Sea Foam through the fuel tank, then did the upper treatment pouring a can down a vacuum hose. I also came armed with a can of Sea Foam Deep Creep penetrating oil. So go the engine cooled back down and got the coils off and out of the way. Shot a little Deep Creep into socket well #8 expecting it to be the most challenging. SURPRISE! I backed it out about an eight of a turn then ran it back in. Worked it out slowly. There was a little black (Carbon?) buildup on the shank below the threads. Pretty much lather, rinse, repeat for 7,6,5,1,2 and 3. Naturally the one with the least visibility and access would cause a problem. Got to #4 and it was not budging. I did not force it. Sprayed the Deep Creep down the well and left well enough alone. Darkness was setting in, so I began installing the new plugs with Anti-Seize applied and I put the coils back on (did not replace them at this juncture). So I had a 7 plugs in, coils on and the connections for the coils and injectors back. Now it was dark. I though I'd see if that remaining plug would come out. I put the socket down the well attached to an extension. I began "hunting" for the socket to seat on the hex head but could not feel it drop into place. I made a few attempts and began turning the extension, felt no resistance. I was frustrated and it was now too dark to continue.

Today I ventured back out. Daylight isn't a great advantage when working on either #4 or #8 but at least it was warm. Again, I eased the socket attached to the extension down the well and again did not feel it seat. I turned the socket several turns in both direction. I felt no resistance did not feel any friction or grinding. Couldn't sense any wobble in the ceramic tip though I could not reach it with a finger, just the magnet and a screw driver. In absolute frustration I put the coil back on and connected everything back up.

The engine cranked and started right up, no misfire. I expected a dead miss on #4. So now I have questions. If I broke the plug initially trying to back it out, wouldn't I have felt it snap? And if I managed to break it without feeling it give, could it still function? I'm likely to contact a dealership and find out what they'll charge to remove and replace this one plug. It's too weird. Also, this after though: I'm at at least the second owner and don't know about any previous plug/coil changes but the plugs I took out are Autolite and I don't know if they are subject to the same breakage as the Motocrafts.

 

[07EddyB]

It's more likely that you have some trash in that well that fell in while you were working. You should be able to see down it with a mirror. Or take a picture with your cell phone. If that plug was broken it wouldn't be firing and the loss of even one cylinder is very noticeable.

 

[Steven G Webb]

It's more likely that you have some trash in that well that fell in while you were working. You should be able to see down it with a mirror. Or take a picture with your cell phone. If that plug was broken it wouldn't be firing and the loss of even one cylinder is very noticeable.

Thanks 07EddyB, I appreciate the insight. Trash falling into that well wasn't even on the radar. It's highly possible since the heater hoses block the view. I did not think a broken plug would fire. This could explain why the paper towel I tried to mop the hole out with came out dry but the socket has oil on it.

 

[1sicbronconut]

One little piece of "junk" will spoil your day on those plugs try a 5.4L in a Expedition with rear heat sometime even worse!! If you have a compressor trying blowing down the hole with a air gun sometimes that will dislodge the "junk" other times had to fish around in the hole with a pick and a small pair of needle nose pliers.

 

[Steven G Webb]

One little piece of "junk" will spoil your day on those plugs try a 5.4L in a Expedition with rear heat sometime even worse!! If you have a compressor trying blowing down the hole with a air gun sometimes that will dislodge the "junk" other times had to fish around in the hole with a pick and a small pair of needle nose pliers.

Thanks 1sicbronconut, I do have a compressor so I'll give that a try. Of course it's the one plug well that is obscured.

 

[94Eddie]

Thanks 1sicbronconut, I do have a compressor so I'll give that a try. Of course it's the one plug well that is obscured.

I recently changed out original plugs at 120k miles and had a decent amount of grit and grime blow out of the wells when I used compressed air to clean them out. Also, if the plugs you are pulling out are Autolite HT1 then I think they are a two piece design similar to the original plugs.

 

[Steven G Webb]

I recently changed out original plugs at 120k miles and had a decent amount of grit and grime blow out of the wells when I used compressed air to clean them out. Also, if the plugs you are pulling out are Autolite HT1 then I think they are a two piece design similar to the original plugs.

Thanks 94Eddie. I appreciate the insight on the plugs.

 

[07EddyB]

Also, if the plugs you are pulling out are Autolite HT1 then I think they are a two piece design similar to the original plugs.

I thought the Autolite's were a one piece replacement for the Motorcraft plugs. I considered them on my first plug change but people were reporting issues with them at the time. Were there different models?

 

[94Eddie]

I thought the Autolite's were a one piece replacement for the Motorcraft plugs. I considered them on my first plug change but people were reporting issues with them at the time. Were there different models?

I believe the HT1 is a two piece design. This comes from research I have done regarding my 2007 Mustang which has the same 2005-2008 4.6L 3V engines that is in the same year Explorers. I am going to tackle changing the original plugs in my 2007 Mustang in the next few months. I decided to go with the revised Ford OEM SP547 one piece plugs.

 

[Bazz270]

The old explorer valve head 4.6 3v engine plugs are two piece even after ford revised em.they changed only the electrode sleeve a bit but they are still 2 piece spark plug.

The updated 4.6 3v valve head only has the one piece design spark plug

 

[Steven G Webb]

Here's an odd twist for anyone still following: I've come down with a cold so I'm in no humor or mood to be working on the Ex. I had a dead battery issue about a month ago, thought I'd left an interior light on overnight. Jump started and moved on without further incident. The plug change extended into a second day and again a dead battery (Did not disconnect the battery, don't hate me). Again, I boosted the truck and took it for a short spin. The truck idles smooth as silk but still has a bit of lurch in the 45-50 MPH range (RPMs jump about 100) under only slight load like taking on a small hill (not enough to cause a downshift). So, today I go out and discover again a dead battery. Not enough juice to open the back glass or turn on the interior lights but the passive alarm light was still flashing.

Made the battery replacement and cranked the truck right up, reset clock and radio (was happy the CEL had turned off from the Sea Foam treatment) running smooth as silk. It occurred to me, if this condition is caused by a coil/plug issue most of the time could a shorting or failing battery also cause the symptoms? The condition has only presented after the engine has come to normal operating temp. Heat can be an enemy to DC circuitry either in the plug or the coil, so could a failing battery getting "warm" contribute to the problem?

I'm only musing right now. I've had off the weekend and go back to work tomorrow so my theory may not stand. I'll find out.

 

[1sicbronconut]

Here's an odd twist for anyone still following: I've come down with a cold so I'm in no humor or mood to be working on the Ex. I had a dead battery issue about a month ago, thought I'd left an interior light on overnight. Jump started and moved on without further incident. The plug change extended into a second day and again a dead battery (Did not disconnect the battery, don't hate me). Again, I boosted the truck and took it for a short spin. The truck idles smooth as silk but still has a bit of lurch in the 45-50 MPH range (RPMs jump about 100) under only slight load like taking on a small hill (not enough to cause a downshift). So, today I go out and discover again a dead battery. Not enough juice to open the back glass or turn on the interior lights but the passive alarm light was still flashing.

Made the battery replacement and cranked the truck right up, reset clock and radio (was happy the CEL had turned off from the Sea Foam treatment) running smooth as silk. It occurred to me, if this condition is caused by a coil/plug issue most of the time could a shorting or failing battery also cause the symptoms? The condition has only presented after the engine has come to normal operating temp. Heat can be an enemy to DC circuitry either in the plug or the coil, so could a failing battery getting "warm" contribute to the problem?

I'm only musing right now. I've had off the weekend and go back to work tomorrow so my theory may not stand. I'll find out.

A bad alternator can cause miss-fires through RFI problems few and far between but I have seen it happen.

 

[Steven G Webb]

Here's an odd twist for anyone still following: I've come down with a cold so I'm in no humor or mood to be working on the Ex. I had a dead battery issue about a month ago, thought I'd left an interior light on overnight. Jump started and moved on without further incident. The plug change extended into a second day and again a dead battery (Did not disconnect the battery, don't hate me). Again, I boosted the truck and took it for a short spin. The truck idles smooth as silk but still has a bit of lurch in the 45-50 MPH range (RPMs jump about 100) under only slight load like taking on a small hill (not enough to cause a downshift). So, today I go out and discover again a dead battery. Not enough juice to open the back glass or turn on the interior lights but the passive alarm light was still flashing.

Made the battery replacement and cranked the truck right up, reset clock and radio (was happy the CEL had turned off from the Sea Foam treatment) running smooth as silk. It occurred to me, if this condition is caused by a coil/plug issue most of the time could a shorting or failing battery also cause the symptoms? The condition has only presented after the engine has come to normal operating temp. Heat can be an enemy to DC circuitry either in the plug or the coil, so could a failing battery getting "warm" contribute to the problem?

I'm only musing right now. I've had off the weekend and go back to work tomorrow so my theory may not stand. I'll find out.

I'll add this as an afterthought: There was a moderate spot of residue on the battery top around the "filler" caps on a 3 yr old battery. Something in there was getting warm enough to push out some vapor or liquid.

 

[D Hook]

Have you put a meter on the battery while the truck is running to see how much voltage is being put out? Bad alternator could be cooking the battery?

 

[RichnMo]

Attempting to solve the rumble strip, engine surge problem I decided to tackle the spark plug replacement yesterday afternoon. Couldn't find a 9/16 spark plug socket (thanks again Ford) so had to go with a deep socket and use a magnet to retrieve the plugs. Ran a can of Sea Foam through the fuel tank, then did the upper treatment pouring a can down a vacuum hose. I also came armed with a can of Sea Foam Deep Creep penetrating oil. So go the engine cooled back down and got the coils off and out of the way. Shot a little Deep Creep into socket well #8 expecting it to be the most challenging. SURPRISE! I backed it out about an eight of a turn then ran it back in. Worked it out slowly. There was a little black (Carbon?) buildup on the shank below the threads. Pretty much lather, rinse, repeat for 7,6,5,1,2 and 3. Naturally the one with the least visibility and access would cause a problem. Got to #4 and it was not budging. I did not force it. Sprayed the Deep Creep down the well and left well enough alone. Darkness was setting in, so I began installing the new plugs with Anti-Seize applied and I put the coils back on (did not replace them at this juncture). So I had a 7 plugs in, coils on and the connections for the coils and injectors back. Now it was dark. I though I'd see if that remaining plug would come out. I put the socket down the well attached to an extension. I began "hunting" for the socket to seat on the hex head but could not feel it drop into place. I made a few attempts and began turning the extension, felt no resistance. I was frustrated and it was now too dark to continue.

Today I ventured back out. Daylight isn't a great advantage when working on either #4 or #8 but at least it was warm. Again, I eased the socket attached to the extension down the well and again did not feel it seat. I turned the socket several turns in both direction. I felt no resistance did not feel any friction or grinding. Couldn't sense any wobble in the ceramic tip though I could not reach it with a finger, just the magnet and a screw driver. In absolute frustration I put the coil back on and connected everything back up.

The engine cranked and started right up, no misfire. I expected a dead miss on #4. So now I have questions. If I broke the plug initially trying to back it out, wouldn't I have felt it snap? And if I managed to break it without feeling it give, could it still function? I'm likely to contact a dealership and find out what they'll charge to remove and replace this one plug. It's too weird. Also, this after though: I'm at at least the second owner and don't know about any previous plug/coil changes but the plugs I took out are Autolite and I don't know if they are subject to the same breakage as the Motocrafts.

Hey I've just been through this and you need to jack up and support r/f with wheel off.then remove inner fender shield. And go at it from under vehicle with inner removed shield just giving additional access. Good luck

 

[reansor]

Attempting to solve the rumble strip, engine surge problem I decided to tackle the spark plug replacement yesterday afternoon. Couldn't find a 9/16 spark plug socket (thanks again Ford) so had to go with a deep socket and use a magnet to retrieve the plugs. Ran a can of Sea Foam through the fuel tank, then did the upper treatment pouring a can down a vacuum hose. I also came armed with a can of Sea Foam Deep Creep penetrating oil. So go the engine cooled back down and got the coils off and out of the way. Shot a little Deep Creep into socket well #8 expecting it to be the most challenging. SURPRISE! I backed it out about an eight of a turn then ran it back in. Worked it out slowly. There was a little black (Carbon?) buildup on the shank below the threads. Pretty much lather, rinse, repeat for 7,6,5,1,2 and 3. Naturally the one with the least visibility and access would cause a problem. Got to #4 and it was not budging. I did not force it. Sprayed the Deep Creep down the well and left well enough alone. Darkness was setting in, so I began installing the new plugs with Anti-Seize applied and I put the coils back on (did not replace them at this juncture). So I had a 7 plugs in, coils on and the connections for the coils and injectors back. Now it was dark. I though I'd see if that remaining plug would come out. I put the socket down the well attached to an extension. I began "hunting" for the socket to seat on the hex head but could not feel it drop into place. I made a few attempts and began turning the extension, felt no resistance. I was frustrated and it was now too dark to continue.

Today I ventured back out. Daylight isn't a great advantage when working on either #4 or #8 but at least it was warm. Again, I eased the socket attached to the extension down the well and again did not feel it seat. I turned the socket several turns in both direction. I felt no resistance did not feel any friction or grinding. Couldn't sense any wobble in the ceramic tip though I could not reach it with a finger, just the magnet and a screw driver. In absolute frustration I put the coil back on and connected everything back up.

The engine cranked and started right up, no misfire. I expected a dead miss on #4. So now I have questions. If I broke the plug initially trying to back it out, wouldn't I have felt it snap? And if I managed to break it without feeling it give, could it still function? I'm likely to contact a dealership and find out what they'll charge to remove and replace this one plug. It's too weird. Also, this after though: I'm at at least the second owner and don't know about any previous plug/coil changes but the plugs I took out are Autolite and I don't know if they are subject to the same breakage as the Motocrafts.

What are you talking about about a 9/16 spark plug socket? They are a standard 5/8 spark plug socket.

 

[Banjoman47]

I believe you said that your did not replace the coils? Correct? If you went to the effort to change out those plugs (which you'll break one at a 98% rate), I would have replaced the coils. Weak and/or bad coils give cause bad Juju.

 

[Bazz270]

What are you talking about about a 9/16 spark plug socket? They are a standard 5/8 spark plug socket.

9/16 for gen4 2007 explorers

 

[Mbrooks420]

You must not have looked very hard. Less than a minute on google and I found a dozen 9/16 plug sockets, including local auto stores and Amazon.

 

[94Eddie]

You must not have looked very hard. Less than a minute on google and I found a dozen 9/16 plug sockets, including local auto stores and Amazon.

I bought the one linked below and it works like a champ in deeper spark plug wells.
Amazon product ASIN B0074HNK9A