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).

It is extremely dangerous and usually not allowed. This can easily trigger the anti-money laundering (AML) controls of China's foreign exchange administration. The remittance account title must closely match the contract buyer and the bill of lading consignee. If payment on behalf is necessary, a legally binding "Tripartite Payment Agreement" must be provided in advance and undergo compliance review by our finance department.

Experience turbo lag and power surge during road tests; check for significant oil accumulation at the turbo intake and intercooler connections (slight oil vapor is normal); and use OBD to read the real-time boost pressure peak to see if it meets factory settings.