This an old trick that I've used on friends cars and it works but
you need to be careful that you don't put too much water into the system
or it will stall and for a hydraulic lock in the chamber and really
screw up you r motor.  Also it must be done on a fully warmed up motor
as the cold water causes the carbon buildup to chill and break away from
the walls and get blown out the exhaust

    DrRufo
    SOCal-81 vanagon