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).
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.
We will check if the vehicle identification number (VIN) is within the official recall batch. If there are any outstanding safety recalls (such as replacing Takata airbags), we will require the original owner to assist in sending it to an official 4S shop to complete the free recall work before the vehicle is deregistered.
