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).

Testing is mandatory. Troubleshooting electrical devices in the car is part of the standard procedure. We will test the window lift motors, mirror folding, air conditioning compressor and fan, electric seat tracks, etc. Any stuttering or failure of electronic components will be recorded.

We conduct basic visual inspections and freezing point tests. If the antifreeze's freezing point is insufficient or the engine oil is severely degraded, we will document it. However, considering the shipping duration, we strongly recommend a comprehensive "Full Fluid Service" upon arrival.