Mercedes-Benz C 230 Kompressor
Proven four-cylinder with optional supercharger. Robust and long-lived; the supercharged variant has good torque. Supercharger magnetic clutch can wear.
Supercharger With Automatic Damping
142 kW and automatic — the supercharger pulls well, but the automatic takes the edge off. Pleasantly quick, not a sports car.
Engine Weaknesses 6
One of the most common weak points of the M111: the head gasket becomes porous and starts leaking between 75,000 and 150,000 km. Typical for older M111 engines.
Symptoms: Coolant loss without visible leak, white exhaust plume, oil-coolant emulsion, engine overheats
The supercharger magnetic clutch and the K40 relay are weak points on the M111 Kompressor. The clutch no longer engages, supercharger boost is absent. K40 relay is often repairable at low cost.
Symptoms: Sudden power loss from approx. 3,000 rpm, supercharger cuts in sporadically or not at all
If spark plugs are left too long in the M111, the voltage load on the ignition coils increases substantially. Always replace ignition coil and spark plug together.
Symptoms: Stumbling under load, engine misfires, ignition failure in individual cylinders, CEL, rough idle
The mass airflow sensor wears and delivers faulty readings. The direct result is power loss and increased fuel consumption. Cheap replacement part, but often overlooked as the cause.
Symptoms: Hesitation under load, elevated fuel consumption, check engine light, power drop
On the M111 supercharged engine the oil level must deliberately be kept below MAX. A blocked crankcase ventilation pushes oil mist into the intake tract and destroys the mass airflow sensor.
Symptoms: Increased oil consumption, MAF sensor fails frequently, slight blue smoke from exhaust, oily intake duct
The engine mounts on the M111 supercharged engine are stressed more heavily than on naturally aspirated variants due to the additional torque. Replacement approximately €500 at a Mercedes dealer.
Symptoms: Vibrations in the cabin especially under supercharger load, clunking on throttle transitions, increased noise at low revs
Vehicle Weaknesses 7
Front strut towers corrode and can break away from the bodywork. Safety-critical failure — affected parts are riveted.
W202 strongly prone to through-rusting at sills, wheel arches and door lower edges. Absence of factory sealant up to 1997 accelerates corrosion. Strut top rust is safety-critical.
Front control arms trap water in internal cavities. Blocked drain holes lead to internal rust. In extreme cases the wheel can detach from the control arm — safety-critical.
Rust on door edges, sills, wheel arches and under door seals. A faulty primer-bath process encouraged early rust formation. First build years particularly affected.
Rubber bushes in the front wishbones wear and develop play. Anti-roll bar mountings wear noticeably quickly.
Wiring breaks affect electric seats and steering column stalks. Classic ageing problem from brittle cable insulation.
Window regulator control units fail through water ingress. SAM module controls lighting and wipers — failures typical on older W202.