Mercedes-Benz E 320 CDI
Inline-six CDI as the top diesel of its era. Powerful and torquey but complex. Check injectors and high-pressure accumulator.
Diesel Standard
145 kW diesel. Functional and economical, emotionless.
Engine Weaknesses 6
Copper sealing washers under injectors burn through from combustion heat. Soot leakage around injectors and seized nozzles are the result. Washers not changed in time require a laborious removal procedure.
Symptoms: Soot deposits visible around injector mountings, rough running, increased consumption, starting problems when engine is hot
Oil supply lines on the OM613 turbocharger coke up, oil flow decreases. The under-supplied turbo wears its bearings prematurely. When replacing, the oil feed line must always be replaced at the same time.
Symptoms: Whistling or rattling noise during acceleration, blue smoke from exhaust, power loss, oil loss at turbo housing
The piezo injectors of the OM613 wear internally at high mileage. Increased return quantities and seating face leaks are typical.
Symptoms: Poor starting, rough idle, individual cylinders fading, increased fuel consumption
Glow plugs corrode in the cylinder head with age. When removed, they frequently snap or the hex rounds off. Drilling out and helicoil insertion required.
Symptoms: Long preheat time in cold weather, starting difficulties in winter, engine warning light; risk of breakage on change
EGR oil drips onto the inlet channel shut-off actuator motor, causing a short circuit. Fuse 24 blows and disables the boost pressure controller and EGR actuator.
Symptoms: Sudden severe power loss, limp mode, engine warning light, multiple fault codes simultaneously
The oil-water heat exchanger at the oil filter housing develops leaks through ageing O-rings. Oil runs onto the A/C compressor and collects in the sump.
Symptoms: Oil patch under vehicle (centre/front), oil film on A/C compressor, dropping oil level, smoke development
Vehicle Weaknesses 6
Bacterial contamination in the electrophoretic coating bath compromised paint adhesion. Rust appears on doors, roof, boot lid and trim strips. Mercedes offered goodwill repairs.
Strut towers corrode severely and can break away from the bodywork. Safety-critical defect: the vehicle can drop uncontrollably.
Wheel arches, sills and strut towers rust heavily. Hidden rust forms beneath the sill cladding.
Front and rear strut towers rust through. At the front the towers can break while driving. At the rear this is an economic write-off.
Electronic ignition lock wears out over time. Key turns but vehicle won't start. Problems worsen in cold weather.
Typical electrical problems: alarm system triggers false alerts, cruise control cuts out, air conditioning shows faults. Cable oxidation is frequently the cause.