2014 Mercedes-Benz E-Class Problems: 11 Known Issues

On the 2007-2014 Mercedes-Benz E-Class, the OM642 3.0L V6 diesel engine oil cooler seals fail, causing engine oil to leak externally into the engine's V, where it runs down the back of the engine and collects at the bottom of the transmission bell housing. The oil cooler sits at the bottom of the engine's V beneath the turbocharger and intake manifolds, making access difficult.

On the 2012-2016 Mercedes-Benz E-Class, on the M276 3.5L V6 (and the related M278 V8) the four camshaft adjusters — the variable-valve-timing phasers bolted to the ends of the cams — wear internally. The locking pin and vane chambers lose their ability to hold position, and oil bleeds out of the adjuster while the car sits. On the next cold start the cam is unsupported for the first second or two of cranking until oil pressure builds, producing a loud metallic rattle from the front of the engine. As wear progresses the adjuster can no longer hold commanded timing and the ECU logs cam/crank correlation and timing-over-advanced faults. Clogged camshaft adjuster magnets (solenoids) and a stretched timing chain often accompany the failure and are commonly misdiagnosed as the sole cause. Owners frequently report the dealer first replacing solenoids or doing an oil change before the adjusters themselves are condemned.

On the 2010-2018 Mercedes-Benz E-Class, the crankshaft position sensor fails due to heat exposure and oil contamination, causing intermittent stalling, no-start conditions, and rough running. The sensor is mounted near the flywheel and exposed to high temperatures.

On the 2012-2016 Mercedes-Benz E-Class M276, mercedes documents a brief secondary-chain tensioner rattle while oil pressure builds on specified M276 engines. The bulletin does not expect consequential damage from that particular condition; persistent noise, warning lights or poor running require separate diagnosis. A model year or correlation code alone does not establish this cause.

On the 2006-2016 Mercedes-Benz E-Class, on the M272 and M276 V6 engines the camshaft position sensors and camshaft adjuster (VVT) solenoids sit in the timing cover, which is notorious for seeping oil. Oil gets past the sensor O-ring and into the electrical connector, then wicks up the wire strands inside the harness insulation by capillary action - owners on MBWorld and BenzWorld report finding oil dripping out of the connector and eventually inside the ME/ECU itself. Early symptoms are camshaft position codes such as P0016/P0017/P0346, rough running, misfires and lack of power. If the oil reaches the engine control module the repair escalates dramatically because the ECU and the full engine harness both need replacing and coding.

On the 2010-2014 Mercedes-Benz E-Class, the W212 (and its W207 coupe sibling) uses an electronic steering column lock that must physically retract a locking pin and report 'unlocked' to the EIS before the car will crank. The tiny DC motor and the plastic gear that drive the pin wear out. Owners report a progressive pattern: first the key has to be inserted and removed several times before the steering unlocks, sometimes with a clicking noise from the column, then eventually the pin never retracts, the steering stays locked and the car will not start at all. Because the ESL is VIN-matched to the EIS and key, it is not a simple parts swap - a used unit will not work without proper matching.

On the 2010-2016 Mercedes-Benz E-Class, mercedes LI82.85-P-055695 directly includes model series 212 and describes a COMAND unit that does not start, remains dark or cannot be operated because of software. It directs a temporary circuit-30 interruption followed by a software update and says not to replace the COMAND unit. The bulletin notes the problem also clears on its own after the car sits for more than about 6 hours, but can return until the software is updated.

On the 2010-2016 Mercedes-Benz E-Class, the AIRMATIC air suspension on the W212 E-Class develops leaks in the air springs (struts), causing the vehicle to sag overnight or drop on one corner. The compressor wears out from overwork trying to compensate for leaking struts.

On the 2011-2016 Mercedes-Benz E-Class, blueTEC diesels use a selective catalytic reduction system that injects AdBlue urea into the exhaust, with NOx sensors upstream and downstream of the SCR catalyst reporting how effectively NOx is being converted. The downstream sensor in particular lives in a harsh, hot, urea-crystallizing environment and degrades or fails outright. When the ECU cannot confirm emissions compliance, US-market emissions law forces the car into a start-prevention strategy: the cluster begins displaying a remaining-starts or remaining-distance countdown, and when it reaches zero the engine will not restart at all. Owners describe the countdown appearing with a full AdBlue tank and no obvious driveability problem, which makes the fault feel arbitrary and is why it generates so much forum traffic. The countdown does not pause simply because the car is parked, so a car left with a low count can become undriveable in the owner's driveway.

On the 2003-2016 Mercedes-Benz E-Class, both the W211 and W212 route sunroof and panoramic-roof water through four drain tubes down the A- and C-pillars. The front tubes exit inside the front wheel liner through small Phillips-shaped openings that clog with leaves, pollen and roof-sealant debris. When they block, water backs up in the roof cassette and runs down the A-pillar into the footwell. Owners on MBWorld and BenzWorld report a damp headliner, water dripping from the A-pillar trim, soaked front or rear carpet after heavy rain, and a persistent musty smell. The real damage is downstream: the front footwells and under-seat area house control modules and connectors, and standing water there causes corrosion, module faults and mold in the HVAC path.

On the 2010-2016 Mercedes-Benz E-Class, the W212 panoramic roof is not sealed — the glass tray is designed to collect water and route it through four drain tubes down the A- and C-pillars to exits behind the front wheel arches and near the rear bumper. Pollen, tree debris and dirt build up in the tray corners and block the drain inlets, or the tube ends kink or pull off their nipples. Once blocked, the tray overflows into the headliner and down the pillars, soaking the front footwells, the rear seat floor and the trim. The consequences are worse than a wet carpet: the front passenger footwell area on these cars houses control modules and connectors, and standing water there causes corrosion-driven electrical faults that are then chased as separate problems. Owners commonly report the leak first as a musty smell or a damp carpet weeks before any visible water appears, and some report leaks even with drains that flow, traced to a failed tray seal or a displaced drain hose behind the trim.