Got lucky with a plug

[rockin1978TA]

My wife called me first thing this morning, and said I got some bad news. I said what, she says the BMW is making a bad noise. She was able to pull over and park it. I had her start it, and listened and it was making a god awful banging noise from under the hood. First thought, lower end. Then when I got to the car before the wrecker picked it up, I checked all the fluids, belts, hoses and such. Started the car it ran fine for me to pull it on the flatbed. It was making what seemed to be an exhaust leak. I got lucky after I got home, did some looking around by the exhaust and found the #6 plug worked its way out. When I changed the plugs in Nov, the #6 was not only hard to get to but seemed like I could only get a few turns in before it would stop turning. I put the plug back in and cranked it down until it couldn't turn anymore, and the car seems to be good now. I think over the last 214000 miles no one else ever changed the back plug, and was just built up with corrosion.

[Ferret]

This happened to me in my old 540i! Just after I bought it it started making what could only be described as a horrific cam rattle.

Turned out plugs 7 and 8 were loose and letting a little gas vent past on every combustion cycle!