Originally Posted by Kartelli
DIY: Spark Plug Change
Mad Props – ELP_JC for the plenum removal steps that helped me get started. I’ve added a few extra comments in addition to his DIY.
General Tips: Start with the Drivers side bank, it has more room to work with, and allow for trial and error for removing the coil packs. BMW also has a special tool for removing the coil packs, I didn’t know this at the time, so I used the ghetto mechanic way. Also, all the plugs were tightened 1 quarter turn beyond “hand tight”. A lot of people recommend to lubricate the treads for easy removal in the future.
I liked your DIY. Performed this today and just a few notes (sorry no photos). The 1/4 turn past hand tight probably isn't going to be tight enough for 12:1 compression cylinder. Once hand tight, my torque wrench, set at 17 lb-ft, took more than a 1/2 turn to "click". You may want to re-check them after a few cycles with a torque wrench (but don't remove them, crush washers are one-time use).
Cyl #8 was a beast and difficult with a torque wrench for sure.
Removing the coils needed no tool, if you turn them back and forth a few times, they pop right out with some muscle.
Old plugs didn't look all that bad (~20k on the engine). I can photograph those if needed.
I did not need to remove the plenum and don't really see the reason.
It was nice having the coil covers off, dust/dirt does get under there, so it was nice to clean those areas.
I cleaned the plug seats with paper towel, shoved into the empty spark plug socket, soaked in a bit of carb cleaner. Just lightly turn it around a few times and you'll pick up junk on the seat where the crush washer sits.
Vehicle fired up and I drove it right away to operating temperature. Car felt the same (which is good!). I reset the mileage indicator for the next month to see if there will be any difference.
Thanks again for taking the time.