What is the Difference Between Engine Seizing and Cylinder Scoring?

[AndresLynn]

Here are the differences between engine seizing and cylinder scoring: 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. In severe cases, adhesive wear occurs, leading to difficulties in starting the engine or causing it to stall on its own. Cylinder scoring is a major engine failure. The root cause of cylinder scoring is the inability to form an oil film between the cylinder wall and the piston rings or piston, resulting in poor lubrication or even dry friction. Engine seizing: Occurs when the piston expands due to excessively high temperatures and gets stuck in the cylinder, causing the engine to fail. Simply put, engine seizing is caused by abnormal combustion that leads to irregular pressure in the combustion chamber. Common causes of engine seizing include design flaws in the car, poor-quality engine oil and poor operating conditions, inaccurate adjustments to the engine's intake and exhaust systems and ignition timing, and excessive engine load.

[LeAdalynn]

Engine seizure and cylinder scoring are both engine issues, but they differ in severity. Engine seizure refers to the piston getting stuck in the cylinder liner, causing the engine to stop abruptly. I've personally experienced this once when my car suddenly stalled on the highway and wouldn't restart—a real headache. This usually happens due to insufficient oil or poor cooling leading to overheating, such as during prolonged traffic jams or aggressive driving with improper oil changes. Cylinder scoring is much milder; it means the cylinder liner surface gets scratched by piston rings, leaving marks. The car can still run, but you'll notice weaker power, increased fuel consumption, and blue smoke from the exhaust as warning signs. This often results from poor oil quality or a dirty air filter allowing dust ingress. The difference is huge: engine seizure requires towing and major repairs or even engine replacement, with terrifying costs; cylinder scoring caught early might only need piston ring replacement and cylinder wall honing. In daily maintenance, I always remind friends to change oil and filters regularly to avoid these problems.