Vehicles using OM646.82x engine list:

Engine OM646.82x

Symptoms:
- Rough idling and loss of power
- Increased smoke emissions, especially black or blue smoke
- Engine warning light (MIL) illuminated
- Difficulty starting or misfires
- Excessive oil consumption or leaks

Diagnosis:
- Check for clogged EGR valve causing poor combustion and rough running
- Inspect turbocharger for wear or failure leading to power loss and smoke
- Examine glow plugs and wiring for faults affecting cold starts
- Test fuel injectors for clogging or leakage causing misfires and roughness
- Look for oil leaks around valve cover gasket and turbo seals
- Scan ECU for fault codes related to sensors (MAF, MAP, crankshaft position)

Fixes:
- Clean or replace the EGR valve to restore proper exhaust gas recirculation
- Repair or replace the turbocharger if worn or damaged
- Replace faulty glow plugs and repair wiring harness as needed
- Service or replace fuel injectors to ensure correct fuel delivery
- Replace valve cover gasket and turbo seals to stop oil leaks
- Update ECU software if available to improve engine management
- Perform regular DPF regeneration and maintenance on DPF-equipped models

Prevention:
- Use high-quality diesel fuel and change fuel filters regularly to prevent injector clogging
- Follow recommended oil change intervals with correct oil grade to protect turbo and engine internals
- Avoid frequent short trips to allow DPF regeneration and prevent soot buildup
- Periodically clean EGR valve and intake system to maintain airflow
- Monitor and address any warning lights promptly to avoid further damage
- Ensure proper engine warm-up before heavy load to reduce wear

Regular maintenance and timely attention to symptoms can significantly improve reliability and longevity of the OM646.82x engine in the specified Mercedes Benz E-Class models.