Unless the previous owner retained the original parts and provided them to us, we usually keep the existing modifications and clearly state in the report "includes non-original modifications." Since the standards for illegal modifications vary by country, buyers should assess whether these modifications can legally pass inspection in their destination country.

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).

The technician will put the vehicle in neutral on the lift, rotate the wheels, and listen for any abnormal metal gear whine from inside the motor reducer, and check for gear oil leaks at the joints of the reducer housing.