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).

Yes. For bulk purchases, we can organize and package the core historical records (transfer records, maintenance summaries) for each vehicle. If an English version is needed, we can provide a basic machine translation reference, and human translation assistance for key technical terms.

Europe and some developed countries have very strict regulations on greenhouse gases. If required by customs, we will specify the exact refrigerant type and charge amount according to the vehicle's air conditioning compressor nameplate in the remarks section of the packing list and commercial invoice.