Solder Seal Gunk Motor Flush is a blend of sludge dissolving solvent which can be added to an engine a few minutes before an oil change to flush out deposits and free valves and rings. Frees up sludge associated with slow city driving. Can be easily used by car owners or professional technicians just before oil changes. Not recommended for turbo charged gasoline or diesel engines. 32 fl. oz. Plastic bottle.