While moving around our Jeep checking for mechanical issues we discovered a problem with the spark plug wires. We wanted to pull a plug and check the burn on a cylinder. Ray tried to pull the boot off and it ripped. When the boot ripped the wire came out of the boot as well. This forced us into changing the plugs and wires.
Replacing Wires and Plugs
We could have just replaced the wires but at this point, it only made sense to pull all of the plugs, check the burn, and replace both plugs and wires. It is not a difficult task and only took about a half-hour. We installed Champion Spark Plugs and Denso Spark Plug Wires which we purchased at Advance Auto. At least we know there are no oil ring issues and that the engine fires as it should with the new plugs and wires.
- Be sure to use an anti-seize lubricant on the threads of the spark plugs. There are a variety of manufacturers and application types. I use the Loctite Silver-Grade Anti-Seize stick. It's not messy and we use it on our Harley Davidson Motorcycles as well. This will prevent the plugs from rusting and sticking. Not using it can cause serious issues with spark plug removal in the future.
- It's also a good practice to apply electronic dielectric grease to the wire boots and on the ceramic of the spark plug. This will help prevent moisture from getting into the contact which could cause a misfire. I used Permatex Spark Plug and Electrical Dielectric Grease on this install. If your going to run your Jeep through a lot of mud and water this will help a lot. It will also help to prevent the boot from drying out and seizing onto the spark plug for easier removal in the future.
- Always check the spark plug gap on the new plug to ensure proper spacing between the center and ground electrode. Spark plugs are supposed to be pre-gapped properly out of the package but sometimes you'll find one that isn't. A plug that isn't gapped properly can cause engine idle issues and misfires.
- When installing the wiring its a good practice to remove and install one wire at a time. Doing so will prevent attaching the wire to the wrong cylinder. If you attach the wires to the wrong cylinders the vehicle might run but it wont run correctly. It can be bad enough that you wont be able to start the vehicle because the firing order has been changed.
Just the Way It Is
As we have been working on the Jeep to be sure it is roadworthy small issues like this have been found. We didn't expect the Jeep would be in perfect condition being a 2008 with 137 K miles. Fortunately we have the mechanical aptitude to make repairs without paying a shop to do them. For the most part though we haven't found any major issues other than that oil leak from the oil pan and critical collar that we repaired a couple of weeks back. We just want to be sure the vehicle is in good running condition so nothing gets damaged further if there is a problem. Eventually, we'll be able to get it out and have some fun in it.