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I have two 2016 Jeep Cherokees with a 3.2 v6. One is a TH and the other one is a Limited. Both have coil issues. Or had coil issues. The TH on an uphill peddle to the floor seem like it was slipping in the rear. It was just the beginning signs of a coil starting to miss.

The Limited I noticed the coil boot or spark plug boot had white on the outside from where it had been firing through the side of it. I went ahead and changed all the spark plugs whenever I did the oil filter / oil cooler replacement. There was a slight amount of oil in the spark plug tube. Sitting at idle it had a miss.

The battery died in the TH for some reason cause coil number five to start misfiring all the time. Number five is the only one that you can get to without taking things off I think. I pulled the coil with the boot and noticed it had been firing through the side with a white spot on the coil boot. Or spark plug boot. It seems to be whichever parts store that you go to they call it different. I went ahead and pulled the spark plug and they put champions in it that are actually iridium. But it didn't survive like the ones from my wife's car. The Limited. I bought a brand new pack of six coils from AutoZone months ago knowing that I needed a change out the ones on the Limited. But after a move and getting the house moved around the way we want to I now can't find them.

Started looking online for the cheapest way to be able to take care of this. I was on O'Reilly Auto parts site and noticed they had a coil boot for $7. Nothing wrong with the coil it is the cold boot. It's just like spark plug wires once they start to Arc through the wire they are no good anymore. So I went and bought a coil Boot and a new spark plug. Not champion.

On the TH the boot was pretty rigid. In other words it wasn't flimsy. So I went ahead and changed out the one in the TH and it fixed the issue no problem.

I use the old boot from the th in order to lower the spark plug down in the hole in screw it pretty much into place. It's tight back there so you have to have exactly the right length of extension otherwise you have to break apart your ratchet and then pull the extension off of the socket in order to get things in and out. So trying to lower the spark plug down in the hole with the socket and extension was not an option.

Anyway the th is done. I went to my wife's car which it's number one plug that was missing. I pulled the air intake box in order to get to it. Whenever I pulled the coil off the boot was limp. It is totally oil soaked. I also pulled number three and it is the same. So I'll end up having to change out the gasket on the rear valve cover. The seals are around the spark plug hole. So the cover on the boot that sits down on top of the valve cover only keeps moisture and dirt out. Once the oil seals that are at the top of the spark plug cylinder hole go bad then the oil leaks into the cylinder. And it migrates its way into the boot in the spring. I replaced the spark plug and the boot and cleaned the connector where the spring sets on the coil. Worked out perfectly no issues.

So I didn't replace the coil on either car and both are working perfect.

AutoZone has a whole set of these boots for $22. Since I have exactly the same motor in both cars if I spend the $22 then I can use it on both cars. Plus they have a lifetime warranty. So if one of those boots goes bad I can always go back and get another one.

Hope this helps somebody that is not rich or on a low budget at this time. It fixed me right up. But if it hadn't been for O'Reilly's having the boot in the coil on the same search page I would have never known about it. AutoZone has them listed as spark plug boots.

I'm attaching some pictures so that y'all can see. This is really for the people that are trying to fix their own stuff and not really everyday mechanics.
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The springs in the pictures are different colors. The darker one is from where it's been misfiring. You can actually kind of see where it was misfiring out the side and at the coil itself. The coil boot cost me $7. A new coil would have cost me $37.
 

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2014 TH 3.2, 2" lift, 1" spacers, Steelies
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It never even occurred to me to separate the old boot from the coil head. I always changed mine as whole assemblies.

Note, agree totally that when doing Bank "A" (the rear on the Cherokee for cyl 1/3/5) you need to connect/disconnect multiple socket pieces due to the tight spacing. When doing mine I have to lower first my extension (which has a swivel spark plug head) in the hole and then while holding it, add a small extension and then finally put the socket driver on top. :-( All do-able but more space would have been nice.
 

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Great breakdown on your coil issue…it never occurred to me the coil packs could be repaired. Thanks!

I work with high voltage RF equipment and that arc-thru looks like 90% of the issues I’ve dealt with. Rarely does it occur within the actual HV transformer (coil) due to the low potential differential between windings.
 
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