About halfway through my trip camping near Nevada, I noticed my “Check Engine”1 light came on. I also noticed that at idle, the engine was missing occasionally, just idling poorly. I had been buying gas at strange places, so I went through another tank of gas to be sure it wasn’t the gas. It still continued.
I figured it was the spark plugs (they haven’t been changed ever, which is ~77k miles), so when I got home yesterday, I went by Kragen and got a full set of new plugs and the tools to change them. Damn you, crackhead, for stealing my sockets.
I got home and went to work changing them out. The Jeep has an inline 6-cylinder 4.0L engine, so the cylinders are laid out front to back in a straight line. That means that they pass under all kinds of obstacles, and that the back cylinder is really far from the front of the car, just against the firewall2. In addition, they don’t just have the typical spark plug wires connected to each, they have a single long bar that connects to all of them, held on by more bolts that require wrangling to get out. An hour of struggling with a long and short socket wrench, with and without an extension, up to my elbows in engine parts, I finally got them all changed, and got the bar re-attached.
I cleaned everything up, double checked things, and started her up… and hey, it worked! No more misses… I did a full round of about 10 miles on the freeway to get the engine warmed up and running nicely, and re-checked. Still perfect.
1 Actually, it doesn’t say “Check Engine”, it’s a picture of an engine, which doesn’t really look like an engine. When it first came on, I went “what the fuck is that?” I was in 4WD at the time, so my first thought was it was supposed to look like a transmission, so I pulled over and double checked the Jeep’s manual. They should consider updating it to look like an inline-6. :)
2 This makes me appreciative that the Jeep’s hood can be opened all the way back to rest on the windshield, which gives you a lot more elbow and head room while working.