2012 — 2016
3.0L V6 Turbo Diesel (OM642) - GL350 BlueTEC
Diesel
Check the transmission shift quality at low speeds | Detail: While driving in stop-start traffic, pay attention to any delayed or jerky gear changes, as the 7G-TRONIC transmission may require a fluid flush or solenoid attention in high-mileage examples.
Listen for suspension 'sags' or compressor noise | Check this by: Park the vehicle on level ground and monitor the air suspension height; if the vehicle lowers significantly overnight, the Airmatic struts may be showing their age.
Inspect the 'V' valley of the engine for oil pooling | Check this by: With the engine cover removed, look for signs of oil leaking from the turbocharger intake seals, as this is a known area for minor seeps on the OM642 engine.
Operate the infotainment and electronic seats thoroughly | Check this by: Spend a few minutes testing every button on the driver's seat and the COMAND interface, as the complex wiring looms and control modules can occasionally develop minor electrical gremlins in these luxury models.
Usually time for a major transmission service and inspection of the DPF (Diesel Particulate Filter) system.
Consider a proactive check of the engine mounts and potential replacement of the turbo intake seals to prevent oil dripping onto the swirl motor linkage.
A common point where air suspension components or the compressor may require a refresh to maintain that signature Mercedes ride quality.
Ensure the AdBlue system is filled regularly to avoid limp-home mode triggers.
Stick to a strict 10,000km oil change interval using high-quality, MB-approved low-ash synthetic oil.
Have the brake fluid flushed every two years to keep the electronic braking systems happy.
Regularly clean out the plenum chamber drains to prevent water ingress into the cabin electronics.
Inspect the coolant thermostat housing for signs of brittle plastic, which can eventually lead to cooling system leaks.
Estimated repair costs if issues arise
If the ride height starts to drift, you might eventually need to budget for strut replacement or a compressor rebuild to keep the ride smooth.
Depending on the car's history, you might eventually need to budget for the replacement of the oil cooler seals, which involves a significant amount of labor to reach the component.
If this component needs attention in the future, the estimated cost in NZ is reflective of professional cleaning or replacement of sensors related to the emissions system.
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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