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).

Chinese passenger cars produced after 2005 have fully transitioned to asbestos-free brake pads, clutch plates, and gaskets. However, for export to countries with strict regulations, buyers must pay for sampling and testing by a NATA-accredited laboratory before shipment, and obtain an asbestos-free certificate.

The headliner is considered an "irreversible interior component." If the edges are delaminated or there are deep, hard-to-clean dark water stains, it will directly lead to a downgrade in the interior grade, even if it does not affect driving. We will not use pins or low-quality glue for cosmetic repairs.