What to Do About Engine Cylinder Scoring?
4 Answers
Engine cylinder scoring treatment method: Replace the cylinder block and piston. Engine cylinder scoring is a very serious engine failure, referring to deep grooves being scraped into the cylinder wall, causing the piston, piston rings, and cylinder wall to lose their sealing properties due to friction. This results in reduced cylinder compression pressure and loss of power. If cylinder scoring symptoms persist and continue to be used, the condition will only worsen. Below are the causes of engine cylinder scoring: 1. Engine cooling system failure: Overheating due to leaks, water shortage, and failure to replenish coolant in time. 2. Engine oil level too low: Leading to loss of cylinder sealing and lubrication function. 3. Piston ring damage: Broken piston rings scratch the cylinder wall. 4. Piston pin retaining ring detachment: Detached piston pin retaining rings can scratch the cylinder wall. 5. Use of poor-quality fuel: Poor-quality fuel can cause cylinder scoring. 6. Piston pin protrusion: Protruding piston pins can scratch the cylinder wall. 7. Foreign object entry: Foreign objects entering the cylinder can cause scoring. 8. Insufficient clearance: Too small a clearance between the piston and cylinder wall leads to scoring. 9. Over-tight assembly: Over-tight piston pin assembly causes piston deformation.
I was nearly scared to death last time when my engine seized. It happened on the highway when I suddenly smelled burning and heard the engine making grinding noises. I immediately pulled over, turned off the engine, and called for a tow truck. The mechanic later told me the oil pump had failed, causing the pistons to scrape directly against the cylinder walls, leaving deep grooves. The repair cost me nearly 10,000 yuan, requiring a complete replacement of the cylinder liners and piston rings. Now, during every maintenance check, I keep a close eye on the oil dipstick and make sure to change to full synthetic oil every 5,000 kilometers. If I encounter a similar situation again, I’ll definitely pull over right away and call for help—continuing to drive could completely destroy the engine.
As a veteran truck driver with 20 years of experience, cylinder scoring is something you must take seriously. There are three key steps: immediately stop and turn off the engine—never attempt to restart it; promptly check the oil level—it's likely due to low oil or a faulty oil pump; finally, call for professional towing. The repair process is quite involved—the cylinder block needs to be disassembled to measure scratch depth. If it's less than 0.2mm, polishing can fix it; beyond that requires cylinder liner replacement. I always carry spare oil when driving, avoid stomping the accelerator during cold starts, and regularly clean the crankcase ventilation valve—these habits prevent 80% of cylinder scoring issues.
After my friend's modified car suffered from cylinder scuffing, I finally understood the principle. When the engine overheats or lacks sufficient oil, the piston rings and cylinder wall metal directly rub against each other, generating high temperatures that melt, fuse, and tear the contact points. Ordinary family cars should be alert when the water temperature spikes or the oil light comes on. Repairs require disassembling the engine; minor scratches are treated by cylinder boring, while severe cases require replacing the cylinder block assembly. I recommend using 5W-40 high-viscosity oil for vehicles over three years old, especially those frequently used for long-distance driving. Rebuilt engines always lose some power, so prevention is more important than repair.
