Vehicles using M157.981 engine list:

Engine M157.981

Symptoms:
- Loss of power or reduced engine performance
- Rough idling or misfires
- Excessive oil consumption or oil leaks
- Check Engine Light (CEL) illumination
- Unusual noises such as ticking or knocking from the engine bay
- Turbocharger lag or failure symptoms

Diagnosis:
- Perform a thorough diagnostic scan to check for fault codes related to ignition coils, fuel injectors, or turbocharger sensors.
- Inspect ignition coils and spark plugs for wear or damage, as these are common failure points.
- Check for oil leaks around the valve covers, turbocharger, and oil cooler seals.
- Conduct a compression test to assess cylinder health.
- Examine the turbochargers for shaft play, oil leaks, or boost pressure irregularities.
- Inspect the timing chain and associated components for wear or stretch, as timing issues can cause misfires and noise.

Fixes:
- Replace faulty ignition coils and spark plugs to restore smooth engine operation.
- Repair or replace leaking gaskets and seals to prevent oil loss and contamination.
- Service or replace turbochargers if damaged or worn, ensuring proper boost pressure.
- Replace timing chain components if wear or stretch is detected to avoid engine timing issues.
- Use OEM parts and high-quality lubricants to maintain engine integrity.
- Perform regular oil and filter changes to prevent sludge buildup and component wear.

Prevention:
- Adhere strictly to the manufacturer’s recommended maintenance schedule, especially oil change intervals.
- Use only high-quality synthetic engine oils meeting Mercedes-Benz specifications.
- Regularly inspect ignition components and replace them proactively before failure.
- Avoid aggressive driving that can overstress the turbochargers and engine components.
- Monitor engine performance and address any warning signs promptly to prevent escalation.
- Ensure cooling system is functioning properly to avoid overheating, which can damage engine internals.

By following these diagnostic and maintenance guidelines, owners of vehicles equipped with the M157.981 engine can minimize common issues and maintain optimal engine performance.