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).

Mainstream Chinese automakers rarely publish official English versions of their underlying circuit diagrams. We can provide some models' original Chinese technical documents (PDF) for B2B clients, which you will need to translate for your local mechanics using translation software.

We will directly check the registration certificate (the big green book) and count the number of changes.