2020 — 2026
2.9L Inline-6 Turbo Diesel (OM656) - S350d
Diesel
Cycle through the MBUX infotainment screen and test voice commands; ensure the system is responsive and doesn't lag, as software-related glitches are known to occasionally crop up.
Evaluate the air suspension by switching between 'Comfort' and 'Sport' modes; listen for any persistent hissing or uneven height leveling which could indicate early sensor or compressor fatigue.
Perform a cold start to check for any irregular idle vibrations; the OM656 is refined, so any harsh shaking while stationary is worth investigating with a specialist scan.
Inspect the panoramic sunroof operation; open and close it fully to ensure the mechanism is silent and tracks are clear of debris, as mechanical wear can occur over time.
Usually marks the first major transmission fluid service and potential cooling system inspection.
A common point where suspension components and engine mounts may start showing signs of natural wear.
Time to monitor the diesel particulate filter (DPF) efficiency and potential auxiliary drive belt replacement.
Ensure the digital service history is complete and signed off by a Mercedes-Benz authorised workshop or reputable specialist.
Check that the 48V mild-hybrid battery system reports healthy status during a pre-purchase diagnostic scan.
Verify that the AdBlue tank levels have been topped up regularly as part of the service schedule to keep the emissions system clean.
Confirm the brake pads and rotors have plenty of life, as these are premium parts tailored for the S-Class weight.
Double-check that all recall campaigns related to software updates or electrical wiring have been addressed.
Estimated repair costs if issues arise
While very comfortable, air struts can naturally lose efficiency after high mileage. If this component needs attention in the future, the estimated cost in NZ is usually for one corner, depending on the severity of the leak.
Diesel emission systems can occasionally trigger sensors as they age. Depending on the car's history, you might eventually need to budget for sensor cleaning or a module replacement to keep everything running optimally.
The 9G-TRONIC transmission is excellent, but regular oil changes are key to its longevity. If this service is due, it's a wise investment to ensure smooth gear shifts for years to come.
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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