Why Does a Car Engine Experience Cylinder Scoring?
3 Answers
Car engine cylinder scoring can occur due to the following reasons: 1. Engine overheating caused by leaks or insufficient coolant in the cooling system that is not replenished in time; 2. Engine oil level too low, leading to loss of cylinder sealing and lubrication function; 3. Piston ring breakage, which scratches the cylinder wall; 4. Piston pin retaining ring detachment, causing scratches on the cylinder wall; 5. Piston rings getting stuck in the ring groove due to carbon deposits, losing their sealing effect; 6. Piston pin protrusion, scratching the cylinder wall; 7. Foreign objects entering the cylinder; 8. Insufficient clearance between the piston and cylinder wall; 9. Overly tight piston pin installation, resulting in piston deformation; 10. Severe piston thermal deformation or melting at the top; 11. Prolonged high-speed or overload operation of the engine.
Last time my car's engine suffered from cylinder scoring, and the repair cost a lot of money, mainly due to improper oil management. Forgetting to change the oil on time led to insufficient lubrication, causing excessive friction between the piston and cylinder, which resulted in scratches. Driving habits are also important—when I was younger, I loved slamming the accelerator, leading to high-speed idling and engine overheating, which made cylinder scoring more likely. A dirty air filter also added to the trouble; when clogged, air couldn’t get in, leading to incomplete combustion and increased friction. Now, I’ve learned to develop good habits, such as changing the oil every 5,000 kilometers, regularly checking the oil dipstick to monitor oil levels, and warming up the engine for a few minutes after a cold start before driving. If I hear unusual noises or see smoke, I stop immediately to check instead of continuing to drive. These lessons taught me that regular maintenance really saves money and hassle. Now, my car’s engine runs smoothly all the time.
There are several common causes of engine cylinder scoring, with lubrication system failure being the primary one. Oil shortage or poor-quality oil can break the lubrication film, causing direct metal-to-metal friction that quickly scratches the cylinder walls. Cooling system malfunctions, such as fan failure or insufficient coolant, can also lead to overheating, where heat buildup damages components. Worn or stuck piston rings can scrape the cylinder block, and a clogged air filter restricts airflow, leading to incomplete combustion that increases friction and temperature. During maintenance, focus on these areas: ensure regular oil changes, check coolant levels, and clean the air filter on schedule. Avoid prolonged high-speed operation while driving, especially under heavy loads. Address abnormal temperature rises or oil pressure warnings promptly. These simple checks can prevent major overhauls.
