The Mercedes-Benz GLE400 has been sold in Australia across two distinct generations. The W166 GLE400 (roughly 2015–2019) used a 3.0-litre M276 biturbo V6 petrol with a 7G-TRONIC Plus automatic. The second-generation W167 GLE400d, arriving for the 2019–2020 model years, replaced it with the OM656 3.0-litre inline-six turbo-diesel, a 9G-TRONIC nine-speed automatic, and EQ Boost 48-volt mild-hybrid technology. Both are capable, comfortable large luxury SUVs — but used examples carry above-average running costs and some well-documented weak points that buyers need to understand before committing.
OM656 Diesel — DPF, EGR and AdBlue (W167 GLE400d)
The OM656 is a refined diesel engine, but it brings the full modern emissions stack — diesel particulate filter (DPF), exhaust gas recirculation (EGR), and AdBlue selective catalytic reduction (SCR) — each of which can become a cost centre on used examples.
- DPF clogging: Vehicles used mainly for short urban trips struggle to complete a passive regeneration cycle. Symptoms are reduced power, increased fuel consumption, and eventually limp mode. Forced regeneration typically costs $150–$350; a choked filter that cannot be recovered may need replacement at $2,000–$4,000 fitted.
- EGR carbon build-up: The EGR valve and inlet tracts accumulate carbon deposits on short-trip vehicles. A professional clean is usually $300–$600; valve replacement is needed in severe cases.
- AdBlue and NOx sensor faults: AdBlue must be topped up roughly every 10,000–15,000 km. Some owners report faulty NOx sensors triggering warnings even with adequate fluid. NOx sensor replacement at a dealer can reach $800–$1,500.
W166 GLE400 Petrol — M276 Timing Chain
The earlier W166 GLE400 with the M276 biturbo V6 petrol carries a known timing-chain weakness. The two-stage chain drive can suffer insufficient lubrication when oil changes are deferred, leading to worn tensioners and stretched chains. The telltale sign is a metallic rattle on cold start that clears within seconds. Mercedes updated check valves and tensioner designs to address the issue, but older unserviced examples are still at risk. A full timing-chain service runs $3,000–$6,000 at an independent specialist. Some M276 engines also consume measurable oil between services — check the dipstick regularly and watch for blue-tinged exhaust smoke on start-up.
48-Volt Mild-Hybrid System (W167)
The W167 GLE400d's EQ Boost system integrates a 48-volt belt-driven starter-generator alongside a conventional 12-volt battery. The additional complexity creates failure points that appear on used examples.
- “48V Battery Malfunction” warning: Dashboard alerts relating to the 48-volt lithium-ion battery or the integrated starter-generator are among the more frequently reported electrical complaints on the W167. The DC/DC converter is also a known weak point. In serious cases, the stop/start function is disabled or power delivery becomes erratic.
- 48V harness fire risk — confirmed Australian recall: A manufacturing defect allowed the nut securing the 48-volt wiring harness under the driver’s seat to work loose. Higher-than-normal electrical resistance could cause a fire. This recall (REC-005948) covered 2019–2022 GLE and GLS models in Australia. Verify it has been completed on any used GLE400d you inspect.
AIRMATIC Air Suspension
Many Australian GLE400 examples — across both W166 and W167 — were delivered with the AIRMATIC air suspension system. It delivers genuinely impressive ride quality, but is a significant cost centre once components begin to age.
- Leaking air struts: The rubber air springs crack or develop slow leaks over time. A car sitting lower on one corner, or sagging overnight, is the classic symptom. Replacement air struts cost $1,200–$2,500 per corner fitted.
- Compressor burnout: The air compressor overworks to compensate for leaks and can burn out prematurely. Replacement runs $800–$1,800 fitted.
- Software fault on W167: Mercedes-Benz issued a technical service bulletin covering an AIRMATIC control unit software fault (fault codes C220C06 and C220C04) on the W167/X167 platform that triggers a warning message without any mechanical strut failure. The fix is a control-unit software update at a dealer.
9G-TRONIC Transmission and Transmission Recall (W167)
The 9G-TRONIC nine-speed automatic is generally dependable, but a confirmed safety recall and some reported shift behaviour are worth knowing about. A software fault in the transmission control module could prevent a proper downshift in certain conditions, causing the engine to stall. This issue affected 2019–2023 GLE and GLS (model series 167) in Australia and was addressed by a transmission software update (REC-005922). Some owners also report clunking or hesitation when selecting Drive or Reverse when cold — a dealer software update or valve-body service may be needed on higher-kilometre examples.
Infotainment, Electrical and the Air-Con Drain Recall
The W167 GLE400d uses the MBUX multimedia system with dual 12.3-inch screens. Early software builds could cause the system to freeze or reboot, particularly during wireless phone mirroring. Most cases are resolved with a dealer software update. The front radar sensor (mounted behind the grille) is also a noted fault point, producing “Pre-Safe Functions Currently Limited” warnings from connector corrosion or misalignment; sensor replacement is $1,500–$3,000 at a dealer.
An additional recall (REC-005675) covered 2019–2020 GLE and GLS models where incorrectly fitted air-conditioning drain hoses allowed condensation to enter electrical systems, risking short circuits, fire, and failure of the eCall system and door locks. The remedy was a drain-hose correction at an authorised dealer.
Recalls & Safety
The 2019 and 2020 GLE model years have accumulated multiple recalls lodged with Australia’s Product Recalls Australia (PRA) and vehiclerecalls.gov.au. Key ones for GLE400d buyers include the 48-volt seat harness fire risk (REC-005948), the air-conditioning drain hose electrical fault (REC-005675), and the transmission stall software issue (REC-005922). Check the year-specific recall pages on Carify for the full list:
- Mercedes-Benz GLE400 2019 — recalls and known problems
- Mercedes-Benz GLE400 2020 — recalls and known problems
You can also browse the Carify recalls hub for a full cross-model recall overview.
Buying a Used Mercedes-Benz GLE400? What to Check
- Verify all recalls are closed. Search the VIN on vehiclerecalls.gov.au and ask for stamped dealer records confirming the 48V harness, air-con drain, and transmission software recalls have been carried out.
- Scrutinise the service history. Both the OM656 diesel and M276 petrol punish deferred oil changes. Look for the correct oil specification and regular Mercedes Flexi-Service intervals documented throughout.
- Cold-start the M276 petrol (W166 models). Metallic chain rattle in the first few seconds is a red flag — budget for a specialist timing-chain assessment.
- Check ride height on AIRMATIC cars. The vehicle should sit level; any corner lower than the others, or a hissing noise during the test drive, signals a leaking air spring.
- Scan for 48V warnings on the W167 GLE400d. Stored warnings related to the hybrid system, stop/start, or “battery malfunction” can point to an expensive integrated starter-generator or 48V battery replacement ahead.
- Ask about DPF history on the diesel. Urban short-trip use accelerates DPF blockage — find out the vehicle’s typical usage pattern before buying.
- Run a history check. A PPSR check will reveal finance encumbrances, write-off records, and stolen reports. Pair it with a Carify VIN check for a full picture of the vehicle’s Australian history before signing anything.
The Verdict
The Mercedes-Benz GLE400 is a genuinely accomplished large luxury SUV in either petrol or diesel form, with a refined cabin and strong on-road presence. The W167 GLE400d’s OM656 diesel rewards careful, mixed-use driving and diligent maintenance — neglect the DPF or defer oil changes and costs escalate quickly. The 48-volt mild-hybrid system adds real-world complexity and has produced confirmed Australian recalls on early examples. AIRMATIC suspension, while excellent in operation, is an ongoing cost on higher-kilometre vehicles. Budget for above-average servicing costs, insist on a complete recall history, and commission an independent pre-purchase inspection — then the GLE400 can be a rewarding used buy at the premium end of the market.