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).

Basic perception functions (like Adaptive Cruise Control ACC, Lane Keeping Assist LKA, and Automatic Emergency Braking AEB) rely on the vehicle's local radar and cameras, and can operate normally overseas. However, advanced features that heavily depend on high-precision maps and cloud data (like Navigation on Autopilot NOA and Full Self-Driving FSD) cannot be activated overseas.

A cold start reveals problems that a warm engine hides. Ask your inspection agent to perform and film this sequence. First, the start itself: the engine should crank smoothly and settle into a stable idle within a few seconds. Extended cranking, blue or white smoke, or a lumpy idle suggest worn internals or head-gasket issues. Second, listen for timing-chain rattle or metallic tapping in the first ten seconds — cold top-end noise often means deferred maintenance. Third, watch the exhaust on a cold morning: brief white vapor is normal in winter, but persistent blue smoke means oil burning, and sweet-smelling white smoke can indicate coolant leaking into the cylinders. Fourth, have the inspector scan the OBD system right after the cold start; misfire counters and fuel-trim values are most honest when the engine is cold. Ask for a continuous, timestamped video from outside the car before startup through at least five minutes of idling, so you can verify the engine really was cold.