Vehicles using M139.980 engine list:

Engine M139.980

Symptoms:
- Reduced engine performance or power loss
- Unusual knocking or rattling noises from the engine
- Check Engine Light (CEL) illumination
- Increased oil consumption or visible oil leaks
- Rough idling or misfires under load

Diagnosis:
- Perform a full diagnostic scan to retrieve fault codes related to ignition, fuel delivery, or turbocharger systems
- Inspect ignition coils and spark plugs for wear or damage, as these are common failure points
- Check for oil leaks around the turbocharger and valve cover gaskets
- Examine the turbocharger for shaft play or unusual noises indicating wear
- Verify proper operation of the variable valve timing system and camshaft sensors

Fixes:
- Replace faulty ignition coils and spark plugs to restore proper combustion
- Repair or replace leaking gaskets to prevent oil loss and contamination
- Service or replace the turbocharger if excessive wear or damage is detected
- Update engine control software if manufacturer recalls or technical service bulletins address known issues
- Clean or replace air intake components to ensure optimal airflow and prevent sensor errors

Prevention:
- Adhere strictly to Mercedes-Benz recommended maintenance intervals, especially oil and filter changes using approved synthetic oils
- Use high-quality fuel to prevent carbon buildup and maintain combustion efficiency
- Regularly inspect ignition components and replace them proactively before failure
- Avoid aggressive driving when the engine is cold to reduce stress on turbocharger and internal components
- Keep the engine bay clean and free of debris to prevent overheating and sensor malfunctions

By following these diagnostic and maintenance guidelines, owners of vehicles equipped with the M139.980 engine can minimize common issues and maintain optimal engine performance.