I had a problem with my drive fluid last weekend that stumped 3 mechanics. Maybe someone here has seen this happen before. My drive fluid is changed every fall by the marina before they winterize. Every spring after we run once or twice I need to add just a smidge of fluid to the reservoir on the top of the engine (merc)to bring it up to the "fill to" line. Remember the "fill to" line is only half way up the reservoir, it's supposed to remain only half full.
When I used the boat this weekend I started smelling something bad. Raised the hatch and that reservoir was overflowing down the exhaust riser. The dark green fluid was pushing through the cap. After I shut down the engine the level dropped to the half way line, maybe a little below the line. Wiped everthing up and the next day, the same exact thing happened. The fluid is in perfect condition. No milk, no foam. Boat has only 5 engine hours since the fall fluid change. No oil slick in the water from the drive either. Boat is five years old and has never done this. Fluid is changed each fall as I said. What could be pushing the fluid out of the reservoir even though it is NOT OVERFILLED. I wasn't running hard, I never do, about 2800 rpm.
When I used the boat this weekend I started smelling something bad. Raised the hatch and that reservoir was overflowing down the exhaust riser. The dark green fluid was pushing through the cap. After I shut down the engine the level dropped to the half way line, maybe a little below the line. Wiped everthing up and the next day, the same exact thing happened. The fluid is in perfect condition. No milk, no foam. Boat has only 5 engine hours since the fall fluid change. No oil slick in the water from the drive either. Boat is five years old and has never done this. Fluid is changed each fall as I said. What could be pushing the fluid out of the reservoir even though it is NOT OVERFILLED. I wasn't running hard, I never do, about 2800 rpm.