Mercedes-Benz E 270 CDI

On the OM647 (5-cylinder engine) injectors frequently fail together. A Mercedes internal bulletin required replacement of all injectors. Single-injector repair leads to subsequent failures.

Symptoms: Hard starting (10–20 attempts), hesitant throttle response, rough running

The crankshaft position sensor fails without warning and prevents engine start or causes sudden engine cut-out while driving.

Symptoms: Engine won't start, engine dies while driving, fault code P0335/P0336

The five-cylinder torque of the OM647 stresses the DMF heavily. LUK recommends preventive replacement from 150,000 km during clutch work. Secondary damage to the clutch and gearbox is possible.

Symptoms: Rattling and clattering at warm idle, judder when pulling away and changing gear, vibrations that transfer through the vehicle, noise disappears when clutch is depressed

The variable swirl flaps in the intake manifold clog with EGR deposits and can break. Repair kits and deletion kits are available.

Symptoms: Rough running at part load, engine warning light, reduced drivability, occasionally debris in the engine

The turbocharger suffers bearing wear from oil coke at high mileages. Short trips or insufficient cool-down time increase the risk.

Symptoms: Whistling or whining turbo noise, blue smoke, power loss, elevated oil consumption

From approximately 200,000 km the OM647 intake tract carbons up with EGR soot and crankcase ventilation oil mist into tar-like deposits. Cleaning or replacement is necessary.

Symptoms: Power loss at full load, smoking on kickdown, high soot output, limp mode with severe carbonisation

Sensotronic Brake Control on pre-facelift models (2002–2006) suffered hydraulic failure. Approximately 1.3 million vehicles were recalled worldwide. Repair cost €2,200–3,500.

The Signal Acquisition and Actuation Module (SAM) fails, particularly when water ingress occurs. Leads to loss of lighting, windscreen wipers and instrument cluster.

SBC electrohydraulic brake (2002–2006) suffered from faulty high-pressure pump control. Two recalls in 2004 and 2005. SBC vehicles require specialist workshop.

AIRMATIC air suspension wears heavily. Air reservoir and compressor fail frequently. Replacement requires complete rear axle disassembly — very costly.

Control arm and track rod end bearings develop play. A common MOT failure point. Regular cause for failed MOT inspection.

SAM modules (front and rear) control lighting, wipers and door functions. Moisture damage and ageing lead to complete failures.