If there is a minor leak in the lines due to bumps, it is possible that the cooling may not work upon arrival. This is a normal physical loss. The cost of vacuuming, pressure testing, and recharging refrigerant at a local auto repair shop is low and is the buyer's responsibility.

The lifespan of rubber sealing strips for frameless doors is usually only 4-5 years. We carefully press the sealing strip at the edge of the roof to check for loss of elasticity and use a high-pressure water gun to wash the seams of the windows to check for direct water leakage due to aging.

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).