What is the cylinder pressure of the Crown?
2 Answers
The cylinder pressure of the Crown is 11 to 13 bar. The working principle of the Crown cylinder is to guide the piston to perform linear reciprocating motion in the cylinder, converting thermal energy into mechanical energy through the expansion of air in the engine cylinder. Gas in the compressor cylinder is compressed by the piston to increase pressure, thereby providing a power source. The classification of cylinders is as follows: 1. Single-acting cylinder: Only one end has a piston rod, where air is supplied from one side of the piston to generate pressure, which pushes the piston to extend, and returns via spring or self-weight; 2. Double-acting cylinder: Air is alternately supplied from both sides of the piston, providing force in one or two directions; 3. Diaphragm cylinder: Uses a diaphragm instead of a piston, providing force in only one direction and resetting via spring; 4. Impact cylinder: Features a middle cover with a nozzle and drain port.
I remember when I helped my friend check his old Crown, the cylinder pressure should generally be around 14 kgf to be normal. If it's too low, say below 10 kgf, the engine would have particular difficulty with cold starts, fuel consumption would skyrocket, and it would lack power when climbing hills. This is usually caused by worn piston rings or poor valve sealing. The common 3.0-liter V6 engine in the Crown has a factory standard pressure between 13 to 15 kgf, averaging 14 kgf. If the pressure is uneven, with a variation exceeding 2 kgf between cylinders, then the engine would need a major overhaul. I recommend using a compression tester during regular maintenance to check and address any issues early to avoid bigger problems down the line. Having driven for decades myself, I know these small details can directly affect daily driving.
