2000 — 2005
2.7L OM612 I5 Turbo Diesel (120kW) - 5G-Tronic Auto
Diesel
While driving, pay close attention to how the 5G-Tronic gearbox transitions between gears; if you feel any hesitation or 'hunting' for gears, it is common to consider whether a transmission service or conductor plate refresh is due.
Check this by lifting the plastic engine cover and looking for 'Black Death'—a carbon buildup around the injectors; in cars of this age, it is worth confirming the copper injector seals are still providing a tight seat.
During low-speed maneuvers like parking, listen for any groaning or whining sounds from the front of the car, as the power steering pumps and racks in this generation occasionally require attention to remain leak-free.
Test every window switch and the central locking system several times; depending on the car's history, the interior switch gear and the All-Activity Module (AAM) can sometimes show signs of age in the NZ climate.
Consider a comprehensive fluid refresh including the differential and transfer case oils to protect the 4WD system.
At this stage, it's common to inspect the front suspension bushings and ball joints, as the weight of the ML can lead to natural wear over time.
Budgeting for a high-pressure fuel pump inspection and potential cooling system overhaul (radiator and hoses) is a proactive way to ensure continued reliability.
Verify the service history for regular transmission fluid and filter changes every 60,000km to 80,000km.
Inspect the fuel lines for any signs of perishing or air bubbles, which are common points of maintenance on the OM612 engine.
Confirm that the 'Low Range' 4WD button engages and disengages smoothly while the vehicle is in neutral.
Check the condition of the serpentine belt and the alternator pulley, as these are vital for the smooth running of the diesel powerplant.
Examine the drain holes under the sunroof and battery tray to ensure they are clear of debris to prevent moisture ingress.
Estimated repair costs if issues arise
In cars of this age, the electronic sensors within the gearbox can occasionally report faults. If this component needs attention in the future, the job typically involves a fresh batch of transmission fluid and a new internal sensor plate.
Depending on the car's history, you might eventually need to budget for replacing the copper crush washers and hold-down bolts on the injectors to prevent carbon leaks and maintain engine efficiency.
If the ride starts to feel less 'Mercedes-like', it is common to consider replacing the front ball joints or power steering hoses. This ensures the heavy SUV remains composed on NZ's winding roads.
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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