We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

Extremely authoritative. The third-party data service providers we connect to legally access the Chinese Public Security Traffic Management Platform, the insurance claims network directly under the China Banking and Insurance Regulatory Commission, and the after-sales databases of major automotive manufacturers. We perform secondary logical verification based on this underlying data.

As rubber seals age, "slight oil seepage (oil stains but no dripping)" is very common in used cars and is not considered a major fault. Our recommendation is: as long as the oil level does not drop abnormally, just clean and monitor it regularly after arrival, without the need to immediately incur high costs to disassemble and replace the seals.