Vehicles using M273.96x engine list:

Engine M273.96x

Symptoms:
- Rough idling and misfires
- Loss of power or hesitation during acceleration
- Engine warning light illumination (Check Engine Light)
- Oil leaks around valve covers and timing chain area
- Excessive oil consumption
- Unusual noises from the timing chain area (rattling or knocking)

Diagnosis:
- Inspect ignition coils and spark plugs for wear or failure, common causes of misfires
- Perform a compression test to check for cylinder sealing issues
- Check for oil leaks around valve cover gaskets and timing chain cover
- Use a diagnostic scanner to read fault codes related to camshaft position sensors and ignition system
- Inspect timing chain tensioners and guides for wear or failure, as timing chain issues are common in M273 engines
- Verify proper operation of the variable valve timing (VVT) system

Fixes:
- Replace faulty ignition coils and worn spark plugs to resolve misfires and rough idling
- Replace valve cover gaskets and timing chain cover gaskets to stop oil leaks
- Replace timing chain tensioners, guides, and chains if wear or damage is detected to prevent timing issues and engine noise
- Clean or replace camshaft position sensors if faulty
- Address VVT system faults by cleaning or replacing solenoids and actuators as needed
- Regular oil changes with manufacturer-recommended oil to maintain proper lubrication and reduce wear

Prevention:
- Adhere strictly to scheduled maintenance intervals, especially oil and filter changes, to prevent sludge buildup and wear
- Use high-quality synthetic oil meeting Mercedes-Benz specifications to ensure proper lubrication of timing chain components
- Periodically inspect ignition components and replace them proactively before failure
- Address oil leaks promptly to avoid engine damage and maintain oil levels
- Monitor engine performance and address warning lights immediately to prevent escalation of issues

By following these diagnostic steps and maintenance practices, owners of vehicles equipped with the M273.96x engine can minimize common issues and maintain reliable engine performance.