Method and apparatus for determining cooling gallery fill in a piston

A system, comprising:

• an engine block having a plurality of cylinder-piston combinations, wherein at least one of the cylinder-piston combinations includes:
• a cylinder;
• a piston positioned in the cylinder and coupled to a connecting rod, the piston having an internal cooling gallery about a circumference of the piston;
• an oil jet for introducing coolant into the cooling gallery;
• and at least one pressure sensor positioned within the piston to detect pressure fluctuations within the cooling gallery;
• and a processor having a program communicatively coupled to the processor, the processor configured to:
• detect cyclical pressure fluctuations within the cooling gallery, via the at least one pressure sensor, during a linear motion of the piston within the engine block;
• determine pressures that occur during the detected cyclical pressure fluctuations;
• and determine a fill ratio of coolant within the cooling gallery based on the determined pressures, wherein the fill ratio is defined by a fraction of a volume of the coolant in the cooling gallery to a total volume of the cooling gallery.