Mercedes-Benz E 350d

The vacuum-controlled coolant pump can develop leaks between the coolant and vacuum circuits. Coolant enters the EGR solenoid valves; an electrochemical reaction creates a fire hazard.

The Bosch CP4 high-pressure pump is more sensitive to fuel contamination than its predecessors. Poor diesel quality can damage the pump and injectors.

Symptoms: Power loss, hesitation, injection system fault codes, in severe cases engine damage from metal swarf

The switchable coolant pump does not reliably seal between the coolant and vacuum circuits. Coolant can overheat electrical solenoid valves — fire risk. Campaign code 2090008.

Symptoms: No direct driver symptoms — preventive recall. Possible coolant loss, electrical faults, unusual odour

Early OM656 units had overly soft roller rocker arms. From engine number 80278367 (10/07/2018) a reinforced version was fitted. Older engines develop camshaft wear and timing chain problems.

Symptoms: Clattering tick in the valvetrain, especially on cold start, increased oil consumption, CEL, rough running

The variable valve lift system Camtronic shows failures at solenoid valves and actuators, especially up to 2022. Camshaft wear generates metal particles in the oil.

Symptoms: Rough idle, knocking noises while driving, elevated oil consumption, variable valve train fault code

DPF, EGR and SCR/AdBlue system are sensitive to frequent short-trip driving. Premature blockages with warning lights are common.

Symptoms: Engine warning light, DPF warning lamp, power reduction in regeneration mode, elevated AdBlue consumption

An incorrectly routed gearbox wiring harness allows water ingress with an increased fire risk. Mercedes issued a recall.

Following software updates, the ECU in individual C238 units was permanently damaged. One owner reported a seven-month workshop stay.

A serial design defect: the tension cables in the soft-top headliner fray and snap after approximately 200–300 roof cycles. Mercedes revised the design from May 2020.

The electric parking brake generates fault messages and seizes, particularly in cold weather. Grinding noises when applying indicate worn components.

The soft-top tension cords fray after just a few hundred opening cycles. A design fault that led Mercedes to carry out goodwill repairs.

At higher mileages the electric motors in the roof kinematics or the hydraulic unit can fail. The roof can then no longer open or close fully.

Brake discs on the W213 show juddering after just a few thousand kilometres. Individual cases report renewed juddering after warranty replacement.

Elevated MOT failure rates at suspension mounts. The double wishbone front axle shows wear at bearings and joints.

Infotainment and driver assistance systems are prone to faults. Brake assist and cruise control warning messages appear without cause. Often resolved via software update.

The electric parking brake is prone to corrosion and seizing. Multiple recall actions for the brake system have been documented.

The electric parking brake generates fault messages and seizes, especially in cold weather. Grinding and creaking noises when releasing are common.

The optional Airmatic air suspension is prone to compressor and air bag failures. Replacement requires removal of the rear axle and is expensive.

The headliner tension cords fray and snap after approximately 200–300 roof cycles. Design fault present until the facelift in 05/2020. Mercedes repair approx. 1,200 EUR, upholstery shop approx. 300 EUR.