Mercedes-Benz G 250 GD
Five-cylinder naturally aspirated diesel with pre-chamber injection. Legendarily reliable, high mileages possible. Keep to oil change intervals.
Off-Road Workhorse of the Old School
The old diesel in the G — reliable, frugal, and with genuine off-road character. Not driving pleasure in the conventional sense.
Engine Weaknesses 7
The Bosch VE injection pump frequently leaks at mileages above 200,000 km, particularly at low temperatures. Fuel drips down the engine block.
Symptoms: Fuel smell and drips on cold start, visible dampness below the injection pump, fuel consumption increases slightly
On 5-cylinder engines with higher mileage, glow plugs seize in the cylinder head. When removed, the plug can shear off, requiring a helicoil insert.
Symptoms: Poor cold start despite fresh battery, rough running in the first few minutes
The OM602 is prone to head gasket failure due to a warped cylinder head, especially after overheating. Failure preferentially between cylinder 1 and timing cover.
Symptoms: External oil loss at the head, hydraulic tappet ticking after cold start, blue smoke when starting, coolant loss, oil film in expansion tank
The timing chain on the OM602 is more prone to stretching than on the four- or six-cylinder. The hydraulic chain tensioner compensates until wear limit. Regular oil changes are essential.
Symptoms: Rattling at cold start for 1–3 seconds, rough running noises from timing cover, in worst case ignition timing offset and power loss
The oil cooler on the OM602 can develop leaking gaskets with age. In the worst case, oil and coolant mix, which seriously endangers the engine.
Symptoms: Oil film or streaks in coolant reservoir, milky oil colour on dipstick, coolant loss without visible external leak
The OM602 starter is prone to brush wear and contact problems in the solenoid at high mileage. Bosch replacement starter approximately €165 as a budget alternative to the OEM part.
Symptoms: No start on first attempt, clicking without engine cranking, starter cranks too slowly, especially in cold or with warm engine
Engine mounts on the OM602 wear with increasing mileage. Budget aftermarket mounts (Corteco) at approximately €24–€50 per unit. Diagnosis with 13mm feeler gauge.
Symptoms: Rough running with noticeable vibrations, droning at certain speeds, clunking on start-up, steering wheel vibrations at idle
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.