2012 — 2015
3.0L V6 Turbo Diesel (OM642) - GL 350 BlueTEC
Diesel
Test drive task: Perform a cold start and listen closely to the timing chain area. | Note: In the OM642 engine, it is common to consider the condition of the timing chain tensioners as the vehicle reaches higher mileage, as a slight rattle on startup can indicate wear.
Test drive task: Shift manually through all gears while driving at low speeds. | Note: The 7G-Tronic transmission benefits from smooth shifts; if you feel any hesitation or 'clunky' changes, it may suggest the transmission fluid is due for a service or the valve body is feeling the effects of age.
Test drive task: Cycle the Airmatic suspension through its height settings while parked. | Note: Air suspension struts can eventually lose their seal integrity. Check that the vehicle rises promptly and does not 'lean' overnight, which is a common observation for older luxury SUVs.
Test drive task: Inspect the 'V' of the engine block near the oil cooler seals. | Note: It is quite common for the oil cooler seals on the OM642 to weep over time, which can create a messy build-up; a quick look with a torch can help you gauge the engine's long-term cleanliness.
Usually the time to perform a major transmission service and check suspension air bellows.
Consider a proactive look at the diesel particulate filter (DPF) and the intake manifold swirl flap actuators.
A high-mileage phase where cooling system components like the water pump and thermostat should be monitored.
Ensure the engine oil and filter are changed at least every 10,000km using the correct Mercedes-approved low-ash synthetic oil.
Keep a close eye on the AdBlue system; ensure the tank is replenished with high-quality fluid to prevent pump crystallization.
Regularly clear the front scuttle panel drains to prevent water ingress into the cabin electronics.
Schedule a transmission flush every 60,000km to keep the 7G-Tronic shifting smoothly.
Check and replace cabin air filters annually to maintain good airflow and prevent moisture buildup.
Estimated repair costs if issues arise
If one of the corners starts to sag, it is often recommended to look at the struts. Depending on the car's history, you might eventually need to budget for these as a pair.
While the seals themselves are inexpensive, this is a labour-intensive job involving deep access into the 'V' of the engine. If this needs attention in the future, the estimated cost reflects the time required for professional installation.
Diesel engines rely on a clean exhaust path. If the DPF reaches its end-of-life capacity, you should prepare for either a deep professional clean or a replacement unit.
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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