Originally Posted by maddog34

i drive an aging Corolla... when i bought it, the engine was smoking under hard acceleration... the previous owner had been pouring "No Smoke" additive into it regularly..
some basic research led me to a known problem with the oil return holes in the lower piston ring land plugging up due to lack of timely oil changes...
the No Smoke plugged the few still unplugged holes up.

in-car tear down... slipped the pistons out.. yep, all return holes plugged... there was over two inches of No Smoke Goop coating the oil pan.. it had nearly plugged up the oil pickup screen too... new bearings, new rings, light hone of cylinders, port/match/cc the head, up the comp. ratio half a point, replace valve guides,.. and drilled oil return holes out to the '95 piston spec... 130k later, no trouble. It reaches redline at least once during every run into the big city... the 10w30 oil is changed every 3k miles.