Mercedes-Benz G 320
Three-valve V6 with individual ignition coils. Smooth and strong. Typical weak points: crankcase breather and intake manifold flaps. High mileages achievable.
G-Class, As Is
G-Class with 158 kW — the experience comes from the vehicle, not the engine.
Engine Weaknesses 7
The camshaft adjuster solenoid on the M112 develops a leak and draws oil by capillary action into the wiring harness. Oil can migrate as far as the engine ECU and destroy it.
Symptoms: Cold-start rattling that disappears after 1–2 seconds, camshaft adjuster fault code, oil traces at wiring connector, later ECU faults
The vacuum hose for the variable intake manifold on the M112 becomes brittle and breaks. The swirl flaps stick. The hose is not available individually — the entire intake manifold is needed.
Symptoms: Power drop, slight hesitation at part throttle, engine runs but without full power
On the M112 V6 the valve cover gaskets become porous over time. Especially the rubber seals on the front cover between the timing cover and engine block fail on virtually all high-mileage M112 engines.
Symptoms: Oil spots on the floor, oil smell after driving, oily engine bay, dropping oil level
The plastic linkage of the variable intake manifold in the M112 typically breaks around 150,000 km. The actuator and tumble flaps freeze in one position — according to forum reports, all M112 engines are eventually affected.
Symptoms: Engine enters limp mode, power drop at higher revs, intake flap fault code, stumbling on acceleration
The M112 V6 has two spark plugs per cylinder sharing a dual-output ignition coil. Neglected plugs prematurely destroy the coils.
Symptoms: Rough idle, individual cylinder misfires, CEL, power loss at cold start
The crankcase ventilation membrane in the M112 wears and causes elevated oil consumption and engine sweating. Engine power can also drop due to false air ingestion.
Symptoms: Oil consumption above 1 L/5,000 km, light oil mist in engine bay, smoke from exhaust
The thermostat on the M112 V6 can stick in the open position. Engine only reaches 70–80°C instead of the target 87°C. Result: increased fuel consumption, poor heater output.
Symptoms: Engine doesn't warm up properly, heater stays cold, increased fuel consumption, temperature gauge permanently low
Vehicle Weaknesses 7
The W463 rusts structurally at window frames (not painted inside from the factory), lower door edges and sills. This problem runs through all model years up to 2018.
The steel ladder frame corrodes at spring seats and cross-members. The double-shell construction is insufficiently sealed and traps moisture.
Window frames are not painted on the inside from the factory and rust heavily. Tailgate and frame sections rust due to missing factory treatment. Full rust treatment up to 7,600 EUR.
Shock absorbers, springs and track rod ends wear out prematurely due to off-road use and the vehicle's high weight.
Worm gear in the steering box shows highest wear in the straight-ahead position. Steering levers and track rod ends are disproportionately often flagged at inspection.
ECU failures often only fixable by complete replacement. Older vehicles with moisture in the engine bay particularly affected. Specialist workshops offer cheaper repair options.
Moisture frequently enters headlights and tail lights, causing short circuits and bulb failures. Tail lights with poor factory sealing are particularly affected.