Vehicles using OM651.901 engine list:

Engine OM651.901

Symptoms:
- Rough idling and loss of power
- Excessive smoke from the exhaust (black or blue)
- Engine warning light (MIL) illuminated
- Increased fuel consumption
- Difficulty starting or misfires

Diagnosis:
- Check for clogged diesel particulate filter (DPF) causing poor exhaust flow
- Inspect turbocharger for wear or failure leading to boost loss
- Test fuel injectors for leaks or malfunction affecting combustion
- Examine EGR (Exhaust Gas Recirculation) valve for carbon buildup restricting flow
- Scan engine control unit (ECU) for fault codes related to sensors or actuators

Fixes:
- Perform DPF regeneration or replace if severely blocked
- Repair or replace faulty turbocharger components
- Clean or replace fuel injectors as needed
- Clean or replace EGR valve to restore proper exhaust gas flow
- Update ECU software if available to improve engine management
- Replace air and fuel filters regularly to maintain system cleanliness

Prevention:
- Use high-quality diesel fuel and adhere to recommended oil change intervals
- Avoid frequent short trips to allow DPF to complete regeneration cycles
- Regularly inspect and maintain turbocharger and EGR system components
- Follow manufacturer service schedules for fuel system and emission controls
- Monitor engine performance and address warning signs promptly to prevent damage

By addressing these common issues proactively, owners of Mercedes Benz vehicles equipped with the OM651.901 engine can maintain reliable performance and extend engine life.