Does repairing engine cylinder scoring count as a major overhaul?
2 Answers
Engine cylinder scoring is considered a major overhaul. Engine cylinder scoring refers to the appearance of obvious longitudinal mechanical scratches and abrasions on the inner wall of the cylinder within the movement range of the piston rings. The root cause of cylinder scoring is the difficulty in forming an oil film between the cylinder wall and the piston rings or pistons, leading to poor lubrication or even dry friction. Below are preventive measures for engine cylinder scoring: 1. Maintain the normal temperature of the coolant between 70°C and 95°C to prevent the engine from overheating; preheating measures should be taken before starting in winter. 2. Operate the engine properly, avoid overloading, refrain from revving the throttle unnecessarily, and do not start the engine without sufficient coolant. 3. Strengthen the maintenance of the air filter to strictly prevent dust from being sucked into the cylinder. 4. Maintain the lubrication system properly to prevent mechanical impurities and carbon deposits from mixing into the engine oil, which could exacerbate cylinder liner wear. 5. Regularly check the engine oil level and top up when it is low.
I've worked in the repair shop for nearly a decade and have seen plenty of engine cylinder scoring issues. Cylinder scoring refers to severe wear on the inner walls of the cylinders, as if they've been scratched by something, which affects the entire engine's performance. Whether repairing it counts as a major overhaul depends on the severity. For minor cases, simply sanding the inner walls might suffice—this is considered a minor repair. For severe cases, the entire engine needs to be disassembled to replace the cylinder liners, pistons, or even piston rings, which clearly qualifies as a major overhaul. A major overhaul is defined as the deep disassembly of core components, taking days to complete, with costs ranging from thousands to tens of thousands, consuming both time and effort, and potentially affecting the car's stability. I recommend regularly changing the engine oil and using high-quality oil to prevent cylinder scoring and extend the engine's lifespan.
