Mercedes-Benz GLE 300d W167

The OM654 has a well-documented valve train weakness shared across Mercedes' 2.0-litre diesel range. The roller-type rocker arms, particularly on the exhaust side, lose lubrication at the contact surface with the camshaft lobes. Early symptoms include a deep rumble or ticking noise audible through the air filter box at idle. If caught early, only the rocker arms and hydraulic tappets need replacing (parts approximately 400-600 euro, labor approximately 6-8 hours). If ignored, the worn rockers score the camshaft lobes, requiring camshaft and bearing housing replacement at 2,000-3,500 euro total. Mercedes specialist shops report this as one of their most frequent OM654 repairs. Failures typically appear between 100,000-180,000 km, with earlier production models (2019-2020) more commonly affected. Mercedes has released updated rocker arms with a revised part number, suggesting the design was improved. Post-2021 engines may incorporate further revisions. Using premium oil and strict oil change intervals (every 15,000 km or annually) helps delay the onset.

The GLE 300d uses a 48V mild hybrid system (EQ Boost) with a small lithium-ion battery. Early 2020-2021 models are particularly affected by premature 48V battery failures. The battery can die while the car is parked, leaving the vehicle unable to start and often unable to be jump-started in the normal way. Mercedes issued Technical Service Bulletins addressing this issue, citing a painted ground contact point, defective battery units, and outdated software as root causes. A new 48V battery part number was released. A class-action lawsuit was filed in the US over this issue. Replacement typically costs 800-2,500 euro depending on whether the dealer or an independent shop performs the work. The replacement battery carries a 24-month warranty. The conventional 12V battery can also drain if the car sits unused for more than 10-14 days.

Many GLE W167 models are equipped with AIRMATIC air suspension. The rubber air springs become brittle and develop cracks over time, allowing air to escape. Symptoms include the car sitting lower on one corner after being parked overnight, or the compressor running excessively to compensate. A single OEM air strut costs approximately 800-1,200 euro per corner, with aftermarket alternatives from suppliers like Arnott available for 400-800 euro. The compressor can also fail from overwork at an additional 600-1,000 euro. Cars with standard steel spring suspension are not affected. When buying, check whether the car has AIRMATIC (visible from the ride height adjustment controls in the centre console) and test by parking overnight to verify the car maintains its ride height. Both sides of an axle should ideally be replaced simultaneously.

The GLE 300d has two NOx sensors in the exhaust system as part of the SCR (Selective Catalytic Reduction) emissions system. These sensors are exposed to extreme heat and can degrade, triggering an alarming 'No restart in X km' countdown warning. A single NOx sensor costs approximately 350-500 euro including fitting. In some cases, the AdBlue injector or metering valve also requires replacement at 300-600 euro. Crystallization of AdBlue around the tank float sensor is another common issue, sometimes resolved by draining and refilling with fresh branded AdBlue. In worst cases, the complete AdBlue tank and pump assembly needs replacing at 1,500-2,000 euro. Cars that sit unused for long periods or use non-branded AdBlue are more susceptible. Regular long-distance driving helps keep the system healthy.

In 2022, Mercedes warned approximately 800,000 owners of OM654 and OM656 diesel vehicles (built January 2017 to October 2021) about a potential fire risk from coolant leaking into the vacuum system via the coolant pump. If coolant contacts certain electrical switch valves, an electrochemical reaction can cause overheating. A formal recall followed with free repairs at dealers. If buying used, verify via VIN that this recall has been completed. If the recall work was performed, the cost is zero. If somehow missed and the pump fails outside recall coverage, replacement costs approximately 500-800 euro.

Some GLE W167 owners report jerky shifting from the 9G-Tronic transmission, especially during cold starts or in stop-and-go traffic. Common causes include valve body calibration issues, sticky solenoids, or low fluid pressure. In many cases, a software update at the dealer resolves the problem at no cost or minimal cost. If the valve body requires replacement, costs can reach 1,500-2,500 euro including labor. Mercedes recommends transmission fluid changes every 60,000-80,000 km, though some marketing materials describe it as a lifetime fill. Regular fluid changes are strongly recommended to extend transmission life.

The MBUX infotainment system in the W167 GLE can occasionally fail to start properly, presenting a completely black centre screen. When this occurs, navigation, reversing cameras, and audio are all unavailable. The issue is typically resolved by a software update at the dealer. In some cases, the head unit module itself needs replacement at 800-1,200 euro. Other reported MBUX issues include CarPlay disconnections, voice control failures, and the system freezing mid-drive. Most software-related issues can be resolved free of charge at a Mercedes dealer via over-the-air or dealer-applied updates.