I"m more of a lurker on this site than a poster, i like to look through the archives and see what i"m doing wrong ect. My old M smokes like a freight train at an idle after it warms up a bit and after a few weeks of that it"ll foul a plug sometimes. So i was in town and picked up some GUNK 5 minute motor flush, says it"s supposed to free up the valves and rings before oil change. I tried it and it helped a ton, now just a little smoke....i"m pretty pleased so far...still might be headin towards a rebuild in the future though...just thought it was a good product for my application. thanks!