MerCruiser Exhaust Water Shutters

The engine does not have to be removed to replace the newer style shutters. The engine usually has to be remove to replace these shutters. ense against exhaust backflow. Newer y-pipes have the shutters located at the top of the pipe.

These can be replaced by removing the cast iron exhaust elbow or sometimes sliding down the 1st rubber bellows. These connectors and shutters are exposed to endless heat cycling and saltwater abuse that can speed up the corrosion process and cause failure. A couple of years ago I had to replace my motor after water rushed in through the exhaust. The shutters can start making a "clakity" noise. Mechanic friend of mine thinks the water shutters in the exhaust on my 04 Merc 5.0L (carbureted) are shot as theres a rattle in the pipes. Many exhaust installations include shutters to prevent water from traveling back up the exhaust and into manifold. You will only have to remove the exhaust elbow from the manifold. Water shutters are located inside of the engine exhaust system pipes, just before the exhaust gas passes thru the transom. Bad shutters will only make noise at or just above idle. PartsVu has engineered these water shutters to match the OEM shutters on many MerCruiser installations and protect water from traveling back into the engine from the exhaust. Some shutters fit down below in the pipe, just before the gases are leaving the boat. When shutters get old they can make noise. If you have an older engine you might have the old 3-piece exhaust y-pipe. The Exhaust Water Shutters are located in the exhaust y-pipe. Many times, when the outdrive is removed or the drive is separated for a water pump replacement, you will find a pieces of these laying around. Without these shutters, lake water can be sucked backwards into the engine when the engine is hot and is being shut down. Other shutters are located up above, where the exhaust gas just leaves the engine. I would recommend replacing the water shutter. The sound is often diagnosed as a bad lifter, connecting rod, gimbal bearing or a bad drive. Eventually a bad shutter can break loose and get stuck down in the exhaust pipe or in the drives exhaust passage. They should be replaced to protect the engine. The shutters help prevent water from running back into the engine under certain circumstances. To replace the shutters in the old 3-piece style t-pipe the engine will have to be removed.