2006 — 2012
5.5L V8 (M273) - GL 500/550
Petrol
Check the Airmatic suspension during start-up | Observation: Listen for any strange compressor noises and ensure the vehicle levels out evenly within a few seconds of starting.
Monitor the engine temperature gauge | Observation: In these 5.5L V8s, it is worth watching that the engine reaches operating temperature smoothly without fluctuating, as cooling system components can become brittle with age.
Cycle through the transmission gears | Observation: While driving at low speeds, feel for smooth transitions; these gearboxes are robust but benefit from regular fluid changes over their lifetime.
Inspect the tailgate and sunroof operation | Observation: Operate the powered tailgate and the sunroof fully to ensure they move without hesitation, as the complex electronics can occasionally show wear in older models.
Usually the time to review the condition of suspension bushings and control arms.
A common point where secondary cooling system components, like water pumps or thermostats, might benefit from a proactive inspection.
Consider having a specialist assess the timing chain tensioner health if there isn't a documented history of this being monitored.
Verify the service history specifically looking for regular engine oil changes using the correct specification oil.
Check for any signs of 'weeping' or oil misting around the engine valve covers.
Ensure all air conditioning zones are blowing cold, as the HVAC system is quite involved in the X164.
Confirm the panoramic sunroof has been cleaned and lubricated to keep the drainage channels clear.
Inspect the tyre condition across the tread, as alignment issues can be masked by the heavy nature of these luxury SUVs.
Estimated repair costs if issues arise
As the vehicle ages, the air bellows can develop leaks or the compressor may reach the end of its duty cycle. It is worth keeping a reserve for these components to ensure the ride remains as smooth as it was intended to be.
Given the torque of the 5.5L V8, engine mounts can compress over time, potentially leading to increased vibrations at idle. Replacing these is a sensible way to restore that 'bank vault' feeling to the cabin.
While the 7G-Tronic transmission is reliable, it is a complex unit. Budgeting for a professional fluid and filter service is a great way to maintain longevity and ensure smooth gear changes.
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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