The capability of ferrography to aid in diagnosis of engine component faults of EQ-6110 engine is investigated. The oil samples of the engines have been analyzed ferrographically. Enough wear debris have been presented to approve the wear mode. Strip down examination of the tested engines by the end of the reliability trials reveals the specific component problems. Results show that the quantitative ferrography is a sensitive wear measurement technique to detect the early wear of the gears and the scuffing of the cylinder liner and piston ring.