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).
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.
Unless the previous owner retained the original parts and provided them to us, we usually keep the existing modifications and clearly state in the report "includes non-original modifications." Since the standards for illegal modifications vary by country, buyers should assess whether these modifications can legally pass inspection in their destination country.
