All our measuring instruments (especially calipers, paint thickness gauges, and refrigerant pressure gauges) are calibrated quarterly according to ISO quality management system requirements to ensure the data we provide you is objective, accurate, and reliable.

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).

This is a typical case of "secondary damage caused by unprofessional rescue." Many hybrid vehicles require access to "maintenance mode" via engineering computers to allow the water pump to run at full speed for exhaust. We do not bear any moral or financial responsibility for cylinder damage caused by local technicians' misoperation.