The trucks running great with 110k miles on her, but one bit of preventative maintenance has been nagging at me. The manufacturer recommends replacing the spark plugs every 100k miles and we were over due. I’ve changed the plugs twice in the BMW 330i twice now and have been amazed at the difference so I was hoping to see the same improvement with the truck.
You’ll need 8 spark plugs, anti-seize compound, a regular socket wrench, a socket adapter kit, spark plug socket, and probably a metal tube to slide over the socket wrench for more leverage. I used the steering shaft off the kids Razer scooter.
There are two challenges with this DIY. One is getting the spark plug boots off. They simply pop off when the boot is pulled, but they’re on there TIGHT, you may have to twist them to break free, then pull straight back. There’s a metal heat shield around them which gets in the way but there’s enough plug to grab on to. That shield will come off with the plug. One trick I used was to grab the rubber boot with some channel locks and pull them out using the manifold studs for leverage. This worked well for the passenger side plugs, especially for the one in the very back.
The sparks on the drivers side were accessible, but the steering shaft did make things more challenging.
After getting all the boots off the second challenge of getting the spark plugs out presents itself. This actually wasn’t that hard, but you had to be clever. I used the regular socket wrench with a combination of adapters to build extensions long enough to clear the engine, but short enough to avoid fire walls and steering columns. Frequently you could build a socket combination that worked, but couldn’t get leverage to turn the spark plug. That’s where the tubular extension came in handy. For the back passenger side plug I used a 3/8 to 1/4 drive adapter and another 1/4 back to 3/8 adapter to get just the right extension length.
After getting the plugs out, simply apply anti-sieze compound to the threads of the new spark plug, thread them in by hand, then tighten by had with the socket wrench. I don’t know the torque for the splugs, I’ve seen both 22 lbs/ft and 11 lbs/ft so I went with had tight. That should be OK.
On a difficultly scale of 1 to 10 I’d give it a four or five as you have to lean over the truck’s fender and really pull hard on the spark plug boots at weird angles around large obstacles. You need to be clever with a bunch of sockets extensions too. Finally, I pinched a nerve in my back which will take a week to clear up and combined with the upper body muscle soreness from having to pull and twist at wierd angles you’ll be in some pain for a while if you write software for a living.