Mercedes-Benz E-Class W213: common faults & what to check

Does not apply

The OM651 2.1-litre four-cylinder diesel engine has a well-documented failure of the balance shaft drive chain and its plastic chain guide. The chain stretches and the guide disintegrates, causing severe engine knock, loss of power, and in undetected cases complete engine seizure. The failure is often sudden and catastrophic, with plastic debris from the guide entering the engine oil and accelerating main and big-end bearing wear. Mercedes issued extended warranty coverage and recall campaigns in several markets. Full repair requires engine removal and disassembly, making it one of the most expensive diesel repair events on this platform. Early production examples from 2009-2012 are at highest risk.

Example of the part — not this vehicle

Where to look: Lower engine block, balance shaft module, front timing cover assembly

Parts involved: Timing chain.

Does not apply

Piezo injector failure is a known issue on the 2.1 OM651 twin turbo diesel built until about mid 2012, as fitted to the W212 E 220 CDI and E 250 CDI BlueEfficiency. The Delphi piezo injectors can fail, generally beyond 50,000 km, bringing on the engine warning light, limp mode and rough running. Mercedes-Benz first fitted revised piezo injectors and then ran a customer service action that changed the car to solenoid injectors with a new engine ECU and fuel return lines. Ask whether that service action was done, because a car still on the original injectors can need several injectors.

Example of the part — not this vehicle

Where to look: Engine bay, top of the engine under the cover, fuel injectors

Parts involved: Fuel injector.

Does not apply

The OM651's injector copper sealing washers harden and fail, letting combustion gases and soot escape around the injector and bake into a black, tarry crust - the well-known diesel 'black death'. Early piezo injectors on pre-2012 cars are the most affected. Caught early it is a seal-and-clean job; left long, the injector can seize into the head and turn a routine fix into a big one.

Example of the part — not this vehicle

Where to look: Top of the engine at the injector bases in the cylinder head

Parts involved: Fuel injector.

Does not apply

The W212's 7-speed 722.9 automatic can suffer wear in its internal conductor plate and valve body, giving harsh or delayed shifts, occasional limp mode, or gear-selector faults. Neglected fluid accelerates it - the 'lifetime' fill should really be changed around 100,000 km. A conductor plate or valve body is repairable at an independent for far less than a dealer rebuild, but check for it.

Where to look: Automatic transmission - internal conductor plate/valve body

Parts involved: Mechatronic / valve body.

Does not apply

A broken intake manifold flap lever or actuator cam is a known issue on the 3.5 M272 V6 petrol in the W212 E 350. The small plastic part that moves the variable intake runner flaps goes brittle, and carbon from the crankcase ventilation stiffens the flaps until the part snaps. The engine then runs rough at idle, feels flat at low and mid revs and sets an engine warning light with codes P2004, P2005 or P2006. Mercedes dealers replace the whole intake manifold, while independent workshops often fit a metal lever repair kit.

Where to look: Top of engine, intake manifold

Parts involved: Intake manifold.

Does not apply

Pre-facelift W211 E-Class cars (all engines, including the E500 5.0 V8) use Sensotronic Brake Control, an electronic brake-by-wire unit made by Bosch. Faults in the SBC unit can drop the car into its hydraulic back-up mode with a dash warning, where the pedal goes hard and stopping distances grow. Mercedes ran two Australian recalls (PRA 2004/7037 and PRA 2005/7815) and later extended SBC warranty cover in many markets, so ask a Mercedes dealer what still applies to the VIN. Out of cover, a replacement SBC hydraulic unit is expensive.

Where to look: Engine bay, SBC hydraulic unit on the driver side near the brake fluid reservoir

Does not apply

On W211 E-Class sedans fitted with a glass sunroof or panoramic roof, the adhesive holding the glass panel can deteriorate with age and the glass can come away from the car. Mercedes-Benz Australia issued recalls RC2752 (2020), RC2888 (2021) and RC3110 (2023, panoramic roof option 414) to inspect and repair affected roofs free of charge. Cars without a sunroof are not affected.

Where to look: Roof, sunroof or panoramic glass panel

Does not apply

Early W212 E-Class vehicles with build dates from 2009 to 2013 suffered from a documented galvanisation gap in the rear wheel arch inner lip and the lower C-pillar panel junction. Moisture traps in this area cause rust perforation from the inside outward, often invisible until structurally significant. The issue was flagged by European owner clubs and Australian consumer forums. Later production corrected the panel seam. Affected cars that have been driven near the coast or stored in humid conditions are most at risk. Corresponds to Australian arrival years roughly 2009 to 2014 including JDM imports.

Where to look: Rear wheel arches, inner arch lip seam and lower C-pillar junction, both sides

Parts involved: Body corrosion.

Does not apply

W211s fitted with the optional Airmatic air suspension develop leaks in the air struts and can suffer compressor failure. A car that sits level when driven but sags on one corner after standing overnight is the classic sign. Replacement struts and the compressor are expensive, so an Airmatic car that has been neglected can be a money pit; many owners convert to coils.

Where to look: Air struts at each corner and the compressor (usually front of the car)

Parts involved: Air suspension strut.

Does not apply

An oil cooler seal leak is a known issue on the 3.0 OM642 V6 diesel, as fitted to the W211 E 280 and E 320 CDI and W212 E 350 CDI. The oil cooler sits in the V between the cylinder banks, and its original seals harden with heat and leak oil, which runs to the back of the engine and drips from the bell housing. Engines built before about 2010 are most affected; Mercedes-Benz changed to Viton seals and issued service bulletin LI18.30-P-055434, but later engines can still leak. The repair is labour heavy because the intake and turbo plumbing has to come off.

Where to look: Engine V between the cylinder banks; oil runs to the rear of the engine and bell housing

Parts involved: Turbocharger.