Поршень
Receives combustion force and moves up and down inside a cylinder.
Inside each combustion-engine cylinder.
The piston transfers force through its wrist pin to the connecting rod; its crown and ring grooves manage heat and sealing.
The plunger of a syringe pushed by expanding gas.
Oil consumption, noise or compression loss may involve pistons, rings or cylinder wear.
Usually condition-based rather than a routine replacement. Lubrication, overheating and the exact engine affect wear.
Internal-engine work is usually labor-intensive. Diagnosis and the engine code determine the repair scope.
BMW piston shapes are tailored to combustion and valve clearance, so matching bore size alone is insufficient.
BMW petrol and diesel engines; petrol-only systems are identified individually.