SO, cruising around the different sites, it seems like a lot of people are having problems with their mod motors and spark plugs, from the old SOHC 4.6 to the newer DOHC. So.. apparently having been one of the few people on the planet who has never had a plug blow out, stripped the threads or had to use a threadcert to put plugs back in, I consider myself somewhat of an authority on this.
I'm going to assume that those later model cars that have not had spark plug issues is primarily because they are still so new that they haven't been changed yet. Which leads us to the first point.
You have to actually change spark plugs once in awhile.. modern cars can go 150K plus miles without a plug change, but that doesn't mean you should. Since we are talking high performance engines, (or in this case, the truck I use to haul the car with the high performance engine) it pays to pull the plugs at least every 50K miles and have a look. Back in the day, plug reading was an art, you actually tuned by them, today, not so much because of all the electronics. But you say.. if the plugs aren't worn out, why change them, well just change them, and scrounge up an old school plug cleaner, clean the old ones, and put them back in later. Or, put them back in right now.. it doesn't matter. Once you start using one of these you will use them on everything, your hot rod, lawnmowers, chain saws..etc. A source is listed below.
Air Spark Plug Cleaner (harborfreight.com)
Point 2
Ford has built a plug where the threads descend into the combustion chamber.. while there are "problem solver" plugs available that fix that, I don't know of any that say Motorcraft or NGK on them, and the ones that do exist are exponentially expensive. Guys have tried warming up the engines first, doing plugs when the engine is cold.. whatever. this is what has worked for me. First, I prefer the engine to be cold, because I hate getting burned, I then go in, remove the coil packs (more on this later) and start to remove the plug. In almost EVERY case, you will start to loosen it, and it will bind up. This is where the built up funk from the combustion chamber is on the threads, if you continue to force the plug out, you will drag this through the head, destroying the threads, .. so stop. All you need is maybe a full thread loose, then go find some PB Blaster, and spray it into the plug cave. Go have coffee, go eat lunch, call your girlfriend, get on TMO, just let it sit for at least a couple of hours. When you come back, blow out the plug cave with an air hose to get rid of the Blaster, leaves, and whatever else might run into the combustion chamber. go ahead and start removing the plugs, most likely, you will find they will start to come out, then bind again, this is normal, screw the plug back in and out a few threads and you will find the plug will come out without damaging the threads. I'm not sure if the Blaster dissolves the funk or what, but it at least weakens it so the plugs can come out. I then fish the old plugs out with a magnet.
Point 3
Once the plugs are out, gap the new ones, I then run them in with a piece of fuel line, I do this for a couple of reasons, one is that since you can't really see the threads, and are doing it by feel, the rubber hose will slip instead of forcing the plug into the hole when it's cross threaded, so it acts like a safety, in that regard, it also gives you a lot of reach to start the threads, and can bend around the misc objects in the engine bay. By using the rubber hose, you can feel the plugs thread all the way into the taper of the head.. At that point, you only need to tighten the plugs, I'm not sure what the torque value is, and good luck at getting a torque wrench into some of the areas, so I just "tighten" them, remember they are tapered seat plugs, they just need to be tight, there's no reason to twist them out of the engine bay.
Point4
Remember when you pulled the coils off and left half of them in the plug cave stuck on the end of the plug?, What I do, is, I use a bit of white grease on the plug boot. I tried the dialectric stuff, but it crystalizes and IMO is worse than nothing. I don't go nuts with it, but it keeps the coil pack/plug boot intact when removing them.
And just for the record.. it's really no fun to work on the daily driver, or tow vehicle, but nobody wants to get stuck on the side of the road in Resume Speed, Arkansas either. My 2010 Ford F150, 3 valve with 177K miles on it was due for timing chains. Well, actually not, it wasn't making any noise, but I just felt sorry for it, so I put a set in. (my back is trashed so I have a friend that's a Ford master tech do it for me, but I have had plenty of practice). I change oil every 3K to 3500 miles, I use Pennzoil High Mileage in 10w 40. I also dump a pint of Lucas oil stabilizer in when I do it. The timing chains would've gone another 30K miles, no issue, they were remarkably well preserved. Also, when I replaced them I used factory Ford parts, not some Dorman junk.
I also replaced the oil pump, and contrary to popular belief, you don't need to drop the pan on a 4.6 to do this, you can sneak a flex wrench (8mm I think)under the pump and unbolt the pickup, let it drop into the pan (it won't go far) , bolt up the new pump, and fish the pickup out an reattach it to the new pump. If you happen to drop the bolt into the pan, just fish it out with a magnet. Disconnect the sensor on the balancer, crank the engine to prime the pump (I filled the pump as best I could with oil to begin with) once you have oil pressure reconnect the sensor and it will start right away. I think you would agree that the parts look great, especially for 175K plus miles.
Lucas Oil Products Heavy Duty Oil Stabilizer (1 qt.) 10001: Advance Auto Parts
Point 5, When you remove the wiring clip from the coils be very careful, where the coil clip meets the actual coil pack is very weak, the heat only makes this worse. There is a clip on the wiring harness that must be depressed in order for it to be removed. If it doesn't come off, push it back on, trigger the clip and try it again. Some times this coil/ clip interface dies on it's own, but here's no need to force the issue. In this pic, is the weapon that I use to defeat the clip (not shown) it is pointing at the weak spot in the coil pack.
I'm going to assume that those later model cars that have not had spark plug issues is primarily because they are still so new that they haven't been changed yet. Which leads us to the first point.
You have to actually change spark plugs once in awhile.. modern cars can go 150K plus miles without a plug change, but that doesn't mean you should. Since we are talking high performance engines, (or in this case, the truck I use to haul the car with the high performance engine) it pays to pull the plugs at least every 50K miles and have a look. Back in the day, plug reading was an art, you actually tuned by them, today, not so much because of all the electronics. But you say.. if the plugs aren't worn out, why change them, well just change them, and scrounge up an old school plug cleaner, clean the old ones, and put them back in later. Or, put them back in right now.. it doesn't matter. Once you start using one of these you will use them on everything, your hot rod, lawnmowers, chain saws..etc. A source is listed below.
Air Spark Plug Cleaner (harborfreight.com)
Point 2
Ford has built a plug where the threads descend into the combustion chamber.. while there are "problem solver" plugs available that fix that, I don't know of any that say Motorcraft or NGK on them, and the ones that do exist are exponentially expensive. Guys have tried warming up the engines first, doing plugs when the engine is cold.. whatever. this is what has worked for me. First, I prefer the engine to be cold, because I hate getting burned, I then go in, remove the coil packs (more on this later) and start to remove the plug. In almost EVERY case, you will start to loosen it, and it will bind up. This is where the built up funk from the combustion chamber is on the threads, if you continue to force the plug out, you will drag this through the head, destroying the threads, .. so stop. All you need is maybe a full thread loose, then go find some PB Blaster, and spray it into the plug cave. Go have coffee, go eat lunch, call your girlfriend, get on TMO, just let it sit for at least a couple of hours. When you come back, blow out the plug cave with an air hose to get rid of the Blaster, leaves, and whatever else might run into the combustion chamber. go ahead and start removing the plugs, most likely, you will find they will start to come out, then bind again, this is normal, screw the plug back in and out a few threads and you will find the plug will come out without damaging the threads. I'm not sure if the Blaster dissolves the funk or what, but it at least weakens it so the plugs can come out. I then fish the old plugs out with a magnet.
Point 3
Once the plugs are out, gap the new ones, I then run them in with a piece of fuel line, I do this for a couple of reasons, one is that since you can't really see the threads, and are doing it by feel, the rubber hose will slip instead of forcing the plug into the hole when it's cross threaded, so it acts like a safety, in that regard, it also gives you a lot of reach to start the threads, and can bend around the misc objects in the engine bay. By using the rubber hose, you can feel the plugs thread all the way into the taper of the head.. At that point, you only need to tighten the plugs, I'm not sure what the torque value is, and good luck at getting a torque wrench into some of the areas, so I just "tighten" them, remember they are tapered seat plugs, they just need to be tight, there's no reason to twist them out of the engine bay.
Point4
Remember when you pulled the coils off and left half of them in the plug cave stuck on the end of the plug?, What I do, is, I use a bit of white grease on the plug boot. I tried the dialectric stuff, but it crystalizes and IMO is worse than nothing. I don't go nuts with it, but it keeps the coil pack/plug boot intact when removing them.
And just for the record.. it's really no fun to work on the daily driver, or tow vehicle, but nobody wants to get stuck on the side of the road in Resume Speed, Arkansas either. My 2010 Ford F150, 3 valve with 177K miles on it was due for timing chains. Well, actually not, it wasn't making any noise, but I just felt sorry for it, so I put a set in. (my back is trashed so I have a friend that's a Ford master tech do it for me, but I have had plenty of practice). I change oil every 3K to 3500 miles, I use Pennzoil High Mileage in 10w 40. I also dump a pint of Lucas oil stabilizer in when I do it. The timing chains would've gone another 30K miles, no issue, they were remarkably well preserved. Also, when I replaced them I used factory Ford parts, not some Dorman junk.
I also replaced the oil pump, and contrary to popular belief, you don't need to drop the pan on a 4.6 to do this, you can sneak a flex wrench (8mm I think)under the pump and unbolt the pickup, let it drop into the pan (it won't go far) , bolt up the new pump, and fish the pickup out an reattach it to the new pump. If you happen to drop the bolt into the pan, just fish it out with a magnet. Disconnect the sensor on the balancer, crank the engine to prime the pump (I filled the pump as best I could with oil to begin with) once you have oil pressure reconnect the sensor and it will start right away. I think you would agree that the parts look great, especially for 175K plus miles.
Lucas Oil Products Heavy Duty Oil Stabilizer (1 qt.) 10001: Advance Auto Parts
Point 5, When you remove the wiring clip from the coils be very careful, where the coil clip meets the actual coil pack is very weak, the heat only makes this worse. There is a clip on the wiring harness that must be depressed in order for it to be removed. If it doesn't come off, push it back on, trigger the clip and try it again. Some times this coil/ clip interface dies on it's own, but here's no need to force the issue. In this pic, is the weapon that I use to defeat the clip (not shown) it is pointing at the weak spot in the coil pack.
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