2020 — 2023
2.9L Inline-6 Turbo Diesel (OM656) - 210kW GLS350d 4MATIC
Diesel
Cycle through every air suspension setting (Comfort, Sport, Off-road) while stationary and at speed to ensure the compressor engages quietly and the vehicle levels promptly without warning lights.
Listen carefully during low-speed gear changes and acceleration; the 9G-TRONIC transmission should feel seamless—any persistent 'clunking' or hesitation could suggest software or valve body sensitivity.
Check the infotainment system by connecting your phone via Bluetooth and Apple CarPlay/Android Auto; ensure the MBUX system responsiveness is snappy and doesn't flicker, as screen hardware can occasionally require attention.
Inspect the panoramic sunroof seals and the headliner around the A-pillars after a car wash or during a test drive to ensure there is no evidence of moisture, which can be a common point to monitor on large luxury SUVs.
Usually marks the first major service interval where transmission fluid and differential oils are inspected or replaced to ensure long-term smoothness.
A common point to review the health of the suspension components and the DPF (Diesel Particulate Filter) system's accumulation levels.
Consider having a specialist verify the condition of the engine mounts and auxiliary belt tensioners, as these components often reach the end of their design life around this stage.
Follow the Mercedes-Benz 'Service A' and 'Service B' schedule religiously, as these engines thrive on high-quality synthetic oil changes.
Keep a close eye on the AdBlue levels; these systems prefer regular use rather than sitting idle for extended periods.
Regularly clean the drain channels for the sunroof and air intake cowl to prevent moisture buildup inside the cabin.
Ensure the cooling system is checked during every service, as maintaining optimal operating temperatures is key for the longevity of the OM656 diesel engine.
Update the MBUX software via official dealer tools whenever available to keep the electronic interfaces running at their best.
Estimated repair costs if issues arise
Future Budget Planning: These sophisticated systems provide a beautiful ride, but if a strut or the compressor eventually requires attention due to age or debris, it is a significant job. It is wise to set aside funds for this as the vehicle moves toward higher mileage.
Future Budget Planning: Depending on your driving habits, the DPF may eventually require a professional clean or service to maintain engine efficiency. Short urban trips can lead to faster accumulation, so consider this when planning your long-term ownership costs.
Future Budget Planning: The GLS is a substantial vehicle, and the braking system works hard. When the time comes for a full set of performance-rated discs and pads, it is worth budgeting for premium components to maintain that signature Mercedes stopping power.
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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