A piston can seize in a marine engine due to various reasons, including:
Insufficient Lubrication: If the piston does not receive an adequate supply of lubricating oil, the friction between the piston and cylinder wall increases, leading to overheating and potential seizure.
Overheating: Excessive heat within the combustion chamber can cause the piston to expand beyond its designed tolerances. This can result from factors such as coolant system failure, incorrect fuel-air mixture, or prolonged high-load operation.
Contaminants: The presence of foreign particles or contaminants in the engine oil can cause abrasive wear on the piston and cylinder wall, leading to increased friction and the potential for seizure.
Improper Clearances: If the piston-to-cylinder clearance is not within the specified limits, either too tight or too loose, it can affect proper lubrication and thermal expansion, increasing the risk of seizure.
What Action will You Take if Main Engine Piston is About to Seize?
Shut down the engine: If you think your piston is about to seize, the first thing you should do is shut down the engine. This will help to prevent further damage.
Check the oil level: Once the engine is shut down, check the oil level. If the oil level is low, add oil until it reaches the correct level.
Inspect the piston: If you can, inspect the piston for damage. If the piston is damaged, it will need to be replaced.
Change the oil: Once you have inspected the piston, change the oil. This will help to remove any contaminants that may have caused the piston to seize.