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.