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).

Our standard holding period is 3 business days after the deposit is paid (based on the timestamp of the payment slip). The domestic used car market in China moves very quickly, and if we do not receive the bank message confirming the deposit within the specified time, the system will automatically release the hold, and the vehicle will be re-listed for public sale.

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.