Do not use a high-pressure water gun directly! The high-pressure water can instantly damage the fragile aluminum fins of the condenser, leading to a permanent decrease in cooling efficiency. We can only use a low-pressure air gun or a soft brush for surface cleaning.

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).

Absolutely not. The U.S. DOT and EPA have strict import restrictions on non-compliant vehicles. Any Chinese used car that is not 25 years old and not produced to U.S. standards will face mandatory crushing and destruction upon arrival at U.S. ports. We directly reject such non-compliant orders.