It was an old trick to clean the sludge out of the motors. the only time I saw that done was on an old straight eight motor that was so bad, it only held a couple of quarts of oil. They put some atf in it and filled it with oil and had the lady bring it back in al week later and changed it out. That old motor didn't have a filter and theoil back then didn't have detergents in it to help prevent sludge. I'm not sure if the newer cars could --no, i'd say don't try it. Your vehicle may not handle it. Bearings,gakets and ect.