What are the symptoms of engine cylinder scuffing?
4 Answers
Vehicle cylinder scuffing symptoms include weak driving performance, difficulty in acceleration; elevated engine coolant temperature; unstable engine RPM operation accompanied by signs of stalling. Engine cylinder scuffing refers to the appearance of distinct longitudinal mechanical scratches and abrasions on the inner wall of the cylinder within the piston ring's movement range. In severe cases, adhesive wear occurs, leading to difficulties in engine starting or spontaneous stalling. Cylinder scuffing constitutes a major engine failure, fundamentally caused by the inability to form an oil film between the cylinder wall and piston rings/piston, resulting in poor lubrication or even dry friction. Specific causes of engine cylinder scuffing vary but generally fall into three categories: 1. Piston assembly-related causes; 2. Cylinder liner-related causes; 3. Operational usage-related causes.
Last time my friend's car had a cylinder scoring issue, and it was really uncomfortable to drive. The engine felt particularly weak, and the speed would increase very slowly when stepping on the accelerator, especially noticeable when climbing hills—completely different from normal. The most annoying part was the 'clanking' metal friction noise coming from the engine bay, which was especially loud during acceleration. After parking and opening the hood, there was also a pungent burnt smell. The temperature gauge on the dashboard kept rising rapidly, almost reaching the red zone. In such cases, it's really not worth pushing through—we immediately called for a tow truck, as continuing to drive could have completely ruined the entire engine.
If you notice your car suddenly starts burning oil while driving, with blue-gray smoke coming from the exhaust pipe, and the engine noise becomes unusually loud with metallic knocking sounds, you should be alert to the possibility of cylinder scoring. Once I encountered this situation on the highway—the car was shaking violently, acceleration became extremely difficult, and the oil warning light kept flashing. After pulling over to check the dipstick, I found the oil level had dropped significantly. The most obvious sign of cylinder scoring is a dramatic loss of power—no matter how hard you press the accelerator, the RPM just won't rise. In such cases, you must immediately turn off the engine and have it towed to a repair shop for cylinder wall inspection.
The mechanic at the repair shop said that the most obvious sign of cylinder scoring is abnormal engine vibration, especially during cold starts, where you can feel the seat shaking while sitting in the car. The power output also becomes uneven, and the car jerks when you press the accelerator slightly harder. During inspection, you'll notice a sharp increase in oil consumption, with shiny metal particles mixed in the oil. A compression test will reveal significantly lower cylinder pressure than normal. If you continue driving, the engine will quickly overheat or even boil, and the exhaust pipe will emit blue smoke like burning firewood. This usually requires an overhaul, including cylinder boring and piston ring replacement.
