Hey guys, I'd like to get some input from those that have actually done oil/crankcase flushes on engines, using a "flush" of some sort, atf, etc. I put about a quart of atf in a late model BMW to try and clean it out a little, and get a lifter to loosen up and quit knocking. Well, it turns out that this engine wasn't taken care of, and has a lot of sludge inside. The atf cleans so well, that it loosened up a bunch of the sludge, and stopped up the oil pickup for the pump. So, I pulled the pan off, and sure enough, it's a mess. My question is, is flushing the engine actually something that is good for it? My take on it is that if it's got gunk in it to begin with, flushing either doesn't remove it well, or it removes it TOO well, and can cause more problems than it's worth. I know that ATF cleans mucho well........ Normally, if the engine is clean, then a little atf helps with the lifters sticking, or not pumping up. Now I know to be carefull about doing that... Thoughts and experiences?