My buddies Jeep was at my house to do the oil filter housing, which was originally meant to be just the oil pressure sensor, but that stripped out and we needed a new housing. Either way, to do that job, we needed to remove the upper intake manifold to get to it. Since the upper intake manifold was already removed, we decided to put new spark plugs in it, just some preventative maintenance. Not a bad idea at 118k!
First order of business is to remove that upper intake manifold. Follow the steps in this post to get that job done!
Once the upper intake manifold is removed, and that piece of foam is removed, the driver’s side coil packs are in plain sight. There are three of them that are circled below; they will all need to come out to change the spark plugs.
The first step is to push down on the electrical connector that is attached to the coil pack. Push it down and pull it off the coil pack. These can be a little stubborn but it will come off.
Use a 10mm socket to remove the bolt that holds the coil pack in place. I also had an extension on my ratchet to make the job a little easier.
Once the bolt is removed, you should be able to pull the coil pack up and out of the spark plug bore. You may even be able to do this without disconnecting the electrical connector, but for the sake of not breaking anything, it is advised to remove the electrical connection.
Use a 5/8” spark plug socket on an extension to remove the spark plug from the cylinder head. On the passenger side, you may need to slide a smaller extension into the hole, and then connect another smaller one to get it all the way down. Then you can attach the ratchet and loosen the plug.
Check the plug and see if there is any abnormal damage to
the electrodes. This will tell you how
your engine is running and help you to troubleshoot any issues.
Replace the spark plug with the new ones that you have purchased. There is mixed opinions on how you should be replacing them, some people say to put some anti-seize on them, some people say no, some want some dielectric grease, others do not. My recommendation is to do whatever is in the owner’s manual or what the manufacturer says. If that information is not readily available, I will usually opt not to use the anti-seize or the dielectric grease. I just put the plugs in and tighten them to ¼ turn passed hand tight.
Put the coil pack back in place, replace the electrical
connector, and move on to the next one.
So, the driver’s side plugs are easy once you get the upper intake manifold removed. The passenger side plugs are much harder to actually do. There are some brackets in the way and it makes it difficult to get the coil packs off the plugs. It is doable, but you need to have a little patience to remove them without damaging anything. Just be careful and you should have no issues.