How to Determine if a Car Engine Has Cylinder Scoring?
2 Answers
When cylinder scoring occurs, the car will experience jerking motions and the engine will produce significant abnormal noises, with reduced RPM and noticeably decreased power. Cylinder scoring is caused by severe surface damage due to the mutual movement between the piston and cylinder, primarily resulting from localized failure of the lubricating oil film in the moving parts. The cooling efficiency of the engine's cooling system, the quantity and quality of engine oil, and the performance of the supply system are all critical factors that can lead to fatal engine damage. The causes of cylinder scoring are as follows: 1. The clearance between the piston and cylinder is too small; 2. Insufficient lubrication between the piston and cylinder or incorrect oil selection; 3. Failure of the engine cooling system; 4. Low hardness or poor quality of the cylinder itself.
Having driven for many years, I've encountered several instances of cylinder scoring, and identifying it relies on experience and careful observation. First, the engine will produce abnormal noises, such as metallic knocking or scraping sounds during idling or acceleration, completely different from normal engine sounds—more like sharp, crisp noises that make your hair stand on end. Power output will also significantly drop; you'll clearly feel the car lacks strength when starting or climbing hills, and even flooring the accelerator won't help much. Next, check the engine oil condition. Regularly inspect the dipstick—if the oil level drops quickly and requires frequent top-ups, or if the oil contains metal particles, it indicates severe wear is occurring. Exhaust is another telltale sign: after a cold start, check if the tailpipe emits blue smoke, which indicates oil burning, especially noticeable during acceleration. Cylinder scoring is often caused by insufficient lubrication, such as low-quality oil or cooling system failures leading to engine overheating. Untreated, it can cause greater damage like piston failure. For diagnosis, start with self-checks: listen for unusual sounds after starting the car, and inspect the oil and exhaust. If symptoms are obvious, don’t hesitate—take it to a professional shop immediately. Regular maintenance is key: use high-quality oil and replace filters to prevent issues before they arise.
