M-Class (ML)
2 generations · Select a generation to see engines
Which Mercedes Benz M-Class (ML) engine is the most reliable? See common problems, reviews and reliability verdicts across generations and engines.
Frequently asked questions
Which Mercedes Benz M-Class (ML) engine is the most reliable?
ML280/320/350 CDI 3.0 V6 (OM642) (M-Class (W164)) — Maint. Sensitive verdict. The 3.0 V6 CDI (OM642) is the volume ML engine and the one to buy — torquey, refined and well-matched to the big SUV, the same robust six used across C/E-Class, S-Class and the Jeep Grand Cherokee. Two signature niggles to budget for: the oil-cooler seals between the V harden and leak oil (common, labour-involved), and the intake swirl-flap/manifold assembly (the 'Drallklappen' actuator) fails. Plus EGR/DPF and high-mileage injection. With those addressed and good history it's a dependable long-hauler.
Which Mercedes Benz M-Class (ML) engines should you avoid?
None of the Mercedes Benz M-Class (ML) engines listed are rated "Problematic" or "Avoid" — but always check the service history before buying.
What are the most common Mercedes Benz M-Class (ML) problems?
The most commonly reported problems across all Mercedes Benz M-Class (ML) generations and engines: Oil-cooler seal leak, Balance-shaft / idler-gear wear (early), Intake swirl-flap / manifold, EGR / DPF / injectors, Twin-turbo / injection cost.