How to Determine if a Car Engine Has Cylinder Scoring?
2 Answers
Methods to determine cylinder scoring in a car: Observe whether the vehicle has abnormal noises, lack of power, exhaust fumes, blow-by gases, excessive fuel consumption with reduced power, or difficulty starting after shutdown. Causes of cylinder scoring in cars: Poor cylinder lubrication, insufficient break-in period, inadequate cooling, malfunctioning piston rings, use of low-quality fuel, and incorrect repair or assembly. Cylinder scoring is one of the common faults in car engines, referring to deep grooves being formed on the cylinder wall, causing the piston, piston rings, and cylinder wall to lose their sealing ability during friction, leading to reduced cylinder compression pressure and loss of power. Hazards of cylinder scoring to the engine: 1. Reduced cylinder compression pressure, which in severe cases can cause crankcase explosion; 2. Oil being forced up into the cylinder, leading to oil burning; 3. Combustible mixture leaking down, increasing crankcase pressure; 4. Severe smoke from the exhaust pipe, abnormal engine noise, engine malfunction or even stalling, and loss of power.
If my car experiences severe engine shaking or emits blue smoke, I suspect it might be due to cylinder scoring. Last time when I drove a friend's car, after starting, the engine made a metallic grinding noise, followed by a sharp drop in power. Pressing the accelerator didn’t increase speed, which scared me so much that I immediately pulled over. When checking the engine oil, I found a lot of metal shavings on the dipstick—clear signs of piston and cylinder wall friction damage. Cylinder scoring often occurs due to poor maintenance, such as not changing the oil for a long time or poor cooling, leading to high temperatures that melt components. In such cases, I usually shut off the engine immediately and call a tow truck to take it to the repair shop, because continuing to drive will only make things worse. Daily habits are crucial: regularly check the oil level and cooling system, listen for unusual engine noises while running, and avoid flooring the accelerator or long-distance high-speed driving.
