What Causes Engine Cylinder Scoring?

[LeJason]

Engine cylinder scoring can be caused by: engine overheating due to leaks or water shortage in the cooling system that is not replenished in time; severe oil deficiency caused by engine oil leakage or excessive consumption; prolonged high-speed or overload operation leading to excessive temperature; deformation caused by improper assembly of piston pins or cylinder liners. Below are related explanations: 1. Definition of engine cylinder scoring: It refers to 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 may occur, causing difficulties in engine starting or spontaneous stalling. 2. How long can an engine run with a misfiring cylinder? Although it is not recommended to continue driving once an engine has a misfiring cylinder to prevent greater wear or even life-threatening situations, if the vehicle's engine is a four-cylinder, a misfiring cylinder means only three cylinders may be working normally. At idle or low to medium speeds, as long as you avoid sudden acceleration, driving for about ten kilometers should not be a problem. 3. Symptoms of cylinder scoring: Reduced cylinder compression pressure and loss of power; increased crankcase pressure due to downward leakage of combustible mixture, which may cause crankcase explosion in severe cases; oil burning phenomenon caused by upward leakage of lubricating oil into the cylinder; severe smoke from the exhaust pipe; abnormal engine noise; engine malfunction or even stalling.

[OLane]

Last time I went on a long drive, I forgot to check the engine oil and ended up with cylinder scoring—repairing it was heartbreaking. The main reasons are insufficient or contaminated oil leading to lubrication failure, causing the piston to scrape against the cylinder walls due to hard friction. Dirty oil mixed with impurities accelerates wear, and low coolant levels causing engine overheating and expansion can also lead to cylinder scoring. Overloading the engine, such as prolonged high-speed driving or towing heavy loads, increases engine pressure, and combined with worn piston rings causing gas leakage, makes problems more likely. After cylinder scoring, the car shakes violently, accelerates poorly, and sometimes makes strange noises—requiring an expensive engine overhaul. I recommend frequently checking the oil dipstick for level and color, changing the oil regularly (don’t exceed 5,000 km), and ensuring coolant levels are normal before long trips. Don’t wait for the warning light to panic. These small oversights can prevent big troubles.

[McAlan]

Having dealt with numerous cases of cylinder scoring, there are three common causes: insufficient or deteriorated engine oil affecting lubrication, leading to metal parts scraping the cylinder walls; cooling system failures such as radiator leaks or faulty fans causing overheating and expansion; and poor piston ring sealing leading to gas leakage and vibration damage inside the cylinder. Additionally, high-speed driving with overload accelerates wear, and oil contamination, such as mixing with dirt or water, is also dangerous. Simple checks include regularly pulling out the dipstick to check oil level and clarity, and listening for abnormal engine noises. It's recommended to change the engine oil every six months and top up the coolant regularly. This can reduce the risk of cylinder scoring—don't wait until the engine fails to take action.

[DelBrandon]

Car owners often overlook oil maintenance, which is the main cause of cylinder scoring. Insufficient or dirty oil leads to lubrication failure, causing the pistons to scrape the cylinder walls. Insufficient cooling water can also cause overheating and damage. Long-distance driving increases oil temperature and friction, while aging piston rings result in poor sealing, gas leakage, and damage. If problems like loss of power or engine shaking are noticed, stop and check immediately to avoid costly major repairs. Regular maintenance is key—checking the oil dipstick and changing the oil periodically is enough to prevent issues.