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).

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.

We can purchase the hardware (diagnostic device) on your behalf. However, the original online diagnostic accounts (especially those involving anti-theft programming and module matching) have strict domestic IP location and real-name authentication restrictions, making it very difficult to log in stably from overseas for a long time, and we cannot guarantee technical support for this.