Can a Scuffed Engine Cylinder Be Repaired?

[JordanDella]

Engine cylinder scuffing can be repaired, but it requires replacing all the piston rings. For vehicles with cylinder scuffing, a major engine overhaul is necessary, commonly referred to as "cylinder boring." Engine cylinder scuffing refers to the presence of noticeable longitudinal mechanical scratches and abrasions on the inner wall of the cylinder within the range of piston ring movement. In severe cases, adhesive wear may occur, leading to difficulties in starting the engine or causing it to stall unexpectedly. Cylinder scuffing is a major engine failure, and the root cause is the inability to form an oil film between the cylinder wall and the piston rings or pistons, resulting in poor lubrication or even dry friction. There are various specific reasons for engine cylinder scuffing, which can be broadly categorized into three aspects: 1. Piston assembly-related causes; 2. Cylinder liner-related causes; 3. Usage-related causes.

[RachelDella]

I've seen plenty of cases of engine cylinder scoring. Whether it can be repaired depends on the extent of the damage. For minor cases, replacing the cylinder liner and piston rings can fix it. Moderate damage requires cylinder boring and polishing, while severe cases may necessitate a complete engine replacement. There are many causes of cylinder scoring, such as poor oil quality, inadequate cooling, excessive carbon buildup, or prolonged high-load operation. Repair costs are quite high, with basic cylinder boring starting at 3,000-5,000 yuan, and part replacements costing even more. The key is proper maintenance after repair—use full synthetic oil and regularly check the cooling system. Some older cars may still experience oil burning after repair, requiring regular monitoring. If the car is too old or the repair cost exceeds half the car's value, it's often more practical to scrap it and get a new one.

[SanJack]

A while ago, my old car suffered from cylinder scoring. It was repairable, but the question was whether it was worth it. After disassembly, the repair shop found deep scratches on the cylinder walls. They performed cylinder boring and replaced the piston rings, costing over 4,000 RMB. After the repair, the noise was noticeably reduced, but the acceleration still felt a bit sluggish. The mechanic said cylinder scoring is mostly caused by poor maintenance, such as overdue oil changes or unnoticed coolant leaks. If a new car experiences cylinder scoring, it's recommended to handle it through insurance for better cost-effectiveness. For older cars, it's necessary to do the math—sometimes buying a used engine is cheaper than repairing. The key is to perform timely maintenance after repairs, ideally checking the oil every 5,000 kilometers.

[StTravis]

My car-modding buddy says seized engines can still be salvaged - his off-roader got forged pistons after cylinder scoring. Actually, there are two types of cylinder scoring: minor linear scratches (fixable with polishing) and deep grooves (requiring cylinder sleeves). Repair costs mainly depend on labor hours for disassembly and parts - starting from 2,000 RMB for regular cars, easily exceeding 10,000 for luxury models. Always inspect the oil system, as many seizures originate from oil pump or cooler failures. Post-repair, use high-viscosity full synthetic oil for a 2,000km break-in period. However, for engines with multiple prior modifications, the repair risks may outweigh the benefits - upgrading to a reinforced block assembly might be more reliable.