I own a 4.3 liter,with an Alpha I drive(2002). While running on muffs to change the oil, the engine started to overheat. After letting it cool down, I removed the muffs and put the entire outdrive into a large bucket of water with the hose running. This seemed to do the trick. The engine was running at the proper temp, like it did all summer. Does anyone know if the muffs don't allow enough water flow or is the impellar going bad. The impeller has never been changed and I have about 50 hrs on the engine.
