2013 — 2020
3.0L V6 Turbo - S400
Petrol
While driving at low speeds, gently turn the wheel lock-to-lock; listen for any humming or groaning sounds from the power steering pump or rack, as the S400 steering components can show signs of age on NZ's undulating road surfaces.
Check the air suspension by cycling the 'Raise' button on the center console; ensure the vehicle lifts smoothly and reaches its full height within 30 seconds without any dashboard error messages appearing.
Before the drive, check the service history for recent transmission fluid changes, then during your drive, pay close attention to the 2nd to 3rd gear shift to ensure it remains seamless and free of hesitation.
Inspect the infotainment screen and climate control interface by toggling through every menu option; electronic gremlins in the COMAND system can occasionally emerge as these systems approach their mid-life point.
Usually marks the interval for transmission fluid and filter service, which is vital for keeping the 7G-Tronic or 9G-Tronic transmission shifting smoothly.
Often when cooling system components, such as the water pump or plastic coolant lines, may begin to show signs of hardening due to repeated heat cycles.
A common point where secondary ignition components like coils may start to age, potentially affecting engine efficiency or idle stability.
Verify the presence of a stamped service booklet or digital history record showing consistent maintenance at an authorized dealer or reputable European specialist.
Check the condition of the brake discs and pads, as the S-Class carries significant weight and consumes these items faster than smaller vehicles.
Inspect the tires for uneven wear patterns, which can be an early indicator of alignment issues or worn suspension bushings.
Confirm the air conditioning system is blowing cold, as the climate control systems in the S400 are complex and rely on healthy refrigerant levels.
Check for any signs of moisture under the floor mats, which helps ensure that the drain channels are clear and the cabin electronics remain dry.
Estimated repair costs if issues arise
While the S-Class provides a cloud-like ride, the air struts can eventually develop small leaks over time. Future Budget Planning: You might want to set aside funds for a potential strut replacement as the vehicle accumulates higher kilometers.
To maintain that signature Mercedes smoothness, these hydraulic mounts work very hard. If you notice increased vibration at idle in the future, it is often a sign they are due for a refresh.
The S400 relies on an auxiliary battery for various systems. If you see 'Start/Stop Inoperative' warnings, this is a common, manageable maintenance item you should plan for.
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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