For gasoline cars, insist on a compression test: each cylinder should read within 10-15% of the others, and the actual values should match factory specs for that engine. A single low cylinder points to worn rings or valve problems that idle checks will never reveal. A leak-down test goes further. It pressurizes each cylinder and measures how much air escapes and where. Air hissing from the oil filler cap means ring wear; from the intake or exhaust means valve issues; bubbles in the radiator coolant mean a head gasket problem. This is the single most revealing test for engine condition. Also request OBD scan data with freeze-frame records, a coolant system pressure test (to catch hidden leaks), and an inspection of the timing belt or chain condition with service history. For electric vehicles, compression tests don't apply — instead ask for a battery health report from the BMS, motor insulation readings, and a road test logging any inverter or drive-unit fault codes. A written report with photos or video of each test is essential evidence for your records.

We can purchase the hardware (diagnostic device) on your behalf. However, the original online diagnostic accounts (especially those involving anti-theft programming and module matching) have strict domestic IP location and real-name authentication restrictions, making it very difficult to log in stably from overseas for a long time, and we cannot guarantee technical support for this.

No, it is absolutely impossible to get a refund. Not only will there be no refund, but if the proceeds from the port auction of the abandoned cargo are insufficient to cover the exorbitant demurrage and disposal fees, the shipping company and customs will still pursue you (the bill of lading recipient) for the remaining debt through international legal proceedings.