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).

Under international practices and our standard CIF/FOB terms, the THC at the port of origin (China) is borne by the seller; all THC and port miscellaneous charges incurred at the destination port during unloading are to be paid by the buyer (consignee) upon local customs clearance and pickup.

Air suspension is very delicate. If, after the vehicle has been stationary for about 12 hours, the height on one side of the vehicle drops more than 1.5 cm when measured from the wheel arch to the tire, we will determine that there is a slight air leak in the air spring or distribution valve on that side and warn you of the high subsequent repair costs.