2016 Mercedes-Benz GLS 3.0L Diesel · LS66 ACX

The 2016 Mercedes-Benz GLS presents an unusually sparse and notably clean MOT profile across its recorded testing history, with four pass events since 2022 and a single failure dated 8 June 2023 that, crucially, lists no defects or advisory items at all. This points either to an administrative or procedural issue at the test station on that occasion, or to a category of defect not captured within the DVSA database, but the absence of any follow-up advisories on the next pass within the same month suggests no meaningful mechanical correction was required. With the most recent test on 27 June 2025 also returning a clean pass, the roadworthiness picture over the last three years is one of consistent compliance, and there is no accumulated advisory trail to suggest chronic wear points such as corroded brake pipes, perished suspension bushes, or fatigued coil springs that frequently surface on high-mileage luxury SUVs of this vintage. The overall stability of the record is a positive indicator, although the absence of advisories on a vehicle of this age and mileage is itself unusual and warrants careful physical inspection, as minor wear items are virtually inevitable at this point. A recorded odometer reading of 166,935 miles against a ten-year age equates to an annual accumulation of roughly 16,694 miles, which sits well above the typical UK average and places this GLS firmly in high‑mileage territory for its cohort. This level of use places elevated wear demand on the consumable and mechanical components most stressed by sustained road time: the brake discs and pads, the front and rear suspension linkages and bushes, the coil springs, the propshaft universal joints, the air suspension compressor and struts (if equipped with Airmatic), the transmission fluid and torque converter, and the cooling system hoses and thermostat. The lack of recorded mileage gaps in the supplied history suggests continuous service rather than extended standing periods, which is mechanically favourable for the dry components of the drivetrain but raises the probability that wear items have simply been replaced between tests rather than flagged as advisories. Buyers should therefore treat the absence of advisories not as evidence of negligible wear, but as evidence that any failing components have likely been renewed in advance of the test. On a physical inspection and accompanied test drive, attention should be directed first to the suspension, as the GLS platform is sensitive to worn upper and lower control arm bushes, worn anti-roll bar drop links, and tired coil springs or air springs, all of which manifest as clonking or knocking noises over speed humps, uneven cornering attitudes, and a general looseness in the steering response over broken surfaces. The brake system should be examined for lipped or scored front discs, binding calipers that cause pulling under firm pedal application, and any corrosion visible on the flexible brake hoses or underbody pipe runs, particularly around the inner arches where road salt accumulates. Steering should be tested for any play at the straight-ahead position or any vagueness during slow-speed manoeuvres, both of which can indicate worn tie rod ends or a fatigued steering rack, while the transmission should be observed across a wide throttle range for any shunt, hesitation, or harsh downshifts that would suggest degraded ATF or internal clutch wear consistent with sustained high-mileage use. Finally, the engine bay and underbody should be examined with the vehicle raised on a ramp if possible, paying particular attention to evidence of oil misting or weeping from the valve cover gaskets, oil filter housing, and the timing chain cover area, all of which are recognised wear points on the M276 V6 petrol and OM642 diesel engines commonly fitted to this model. Coolant hoses and the expansion tank should be checked for any signs of crystallisation or staining that would indicate past or present leaks, and the underbody should be inspected for corrosion on the subframe mounting points, suspension turret seams, and exhaust heat shields, particularly given the high road mileage accumulated through British winters. A thorough scan for any fault codes stored in the transmission control module, air suspension module, and engine ECU is strongly advised, as intermittent electrical and sensor faults on the GLS often do not surface as MOT advisories but can be expensive to rectify. With the MOT history itself offering no negative signals, the mechanical case for this vehicle rests almost wholly on the diligence of the present inspection.