2018 — 2020
4.7L M278 V8 Twin-Turbo - S550/S500 late production
Petrol
Check the air suspension leveling by observing the car from the outside while it is parked on a flat surface. | Advice: In cars of this age, it is common to consider that the Airmatic struts may eventually show signs of wear. Ensure the vehicle doesn't 'sag' overnight or after a short drive.
Check the engine startup cold by listening closely for any rattling sounds from the engine bay during the first 5 seconds. | Advice: The M278 engine uses cam phasers and timing chain tensioners that, depending on maintenance history, may require monitoring to ensure smooth operation.
Check this by accelerating gently from a stop and feeling for any hesitation or 'shudder' in the 9G-TRONIC transmission. | Advice: While the 9-speed transmission is advanced, smooth, consistent shifts are a good sign of healthy adaptive learning and fluid condition.
Check the interior electronics by cycling through the COMAND system and the ambient lighting controls. | Advice: With the W222's extensive digital architecture, it's wise to verify all infotainment features, as intermittent screen flickers can sometimes indicate aging wiring or module fatigue.
Usually time for a major transmission fluid service and potential spark plug inspection.
A common point to review the health of the air suspension compressors and engine mount condition.
Consider a thorough cooling system health check, including the water pump and thermostat housing.
Prioritize a pre-purchase inspection from an independent specialist familiar with Mercedes-Benz diagnostics.
Verify the service book shows consistent oil changes, ideally with high-quality synthetic lubricants.
Confirm that the brake rotors and pads have sufficient life, as these are performance components suited to a heavy luxury sedan.
Check the tire wear patterns to ensure the alignment is true, as the W222 is sensitive to suspension geometry settings.
Review the battery health report, as the electronic systems in these cars are heavily dependent on a strong power supply.
Estimated repair costs if issues arise
If the air struts or compressor need attention in the future, it is worth noting that these systems are complex. It is a good idea to set aside funds for this eventually.
Depending on the car's driving history, the rubber mounts that hold the engine and transmission can soften over time, which might lead to minor vibrations.
To keep the twin-turbo V8 running at its best, you might eventually need to budget for maintenance of the fuel injection system components.
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Disclaimer: This report is generated with the assistance of AI analysis based on verified automotive data. While we strive for 100% accuracy, enthusiasts should always conduct physical inspections and consult service records. View Full Disclaimer