According to Au7o's analysis of 5,100+ owner reports, the 2014 Mercedes-Benz E-Class has 12 documented known issues, with 7 rated critical. The most serious are Air Suspension Failure (W212) ($800-$3,000 repair), OM642 Diesel Oil Cooler Leak ($800-$2,500 repair), Camshaft Adjuster Solenoid / Position Sensor Oil Wicking into the Engine Harness and ECU ($250-$4,000 repair), M276 V6 Camshaft Adjuster (VVT Phaser) Wear Causing Cold-Start Rattle and Cam/Crank Correlation Faults ($1,500-$4,000 repair), OM642 Diesel Intake Swirl-Flap Actuator Motor (M55) Failure and Carbon-Clogged Intake Runners Causing Limp Mode ($600-$2,500 repair), Electronic Steering Lock (ESL/ELV) Motor Failure Causing Steering Locked and No-Crank ($300-$1,500 repair) and NOx Sensor Failure in the SCR/AdBlue System Triggering a Start-Prevention Countdown ($600-$1,800 repair).
What are the most common Mercedes-Benz E-Class problems?
According to Au7o's analysis of 5,100+ owner reports, the 2014 Mercedes-Benz E-Class has 12 documented issues. The most frequently reported are: Air Suspension Failure (W212), OM642 Diesel Oil Cooler Leak, Camshaft Adjuster Solenoid / Position Sensor Oil Wicking into the Engine Harness and ECU. Of these, 7 are rated critical and should be addressed promptly.
Is the Mercedes-Benz E-Class reliable?
The 2014 Mercedes-Benz E-Class has 12 known issues documented across 5,100+ owner reports. 7 issues are rated critical: Air Suspension Failure (W212) and OM642 Diesel Oil Cooler Leak and Camshaft Adjuster Solenoid / Position Sensor Oil Wicking into the Engine Harness and ECU and M276 V6 Camshaft Adjuster (VVT Phaser) Wear Causing Cold-Start Rattle and Cam/Crank Correlation Faults and OM642 Diesel Intake Swirl-Flap Actuator Motor (M55) Failure and Carbon-Clogged Intake Runners Causing Limp Mode and Electronic Steering Lock (ESL/ELV) Motor Failure Causing Steering Locked and No-Crank and NOx Sensor Failure in the SCR/AdBlue System Triggering a Start-Prevention Countdown. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Mercedes-Benz E-Class problems?
Repair costs for known Mercedes-Benz E-Class issues range from $100 to $4,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Air Suspension Failure (W212), typically costs $800-$3,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2010-2016 Mercedes-Benz E-Class Air Suspension Failure (W212)?
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. Repairs typically run $800-$3,000. Severity: high.
What is the 2007-2014 Mercedes-Benz E-Class OM642 Diesel Oil Cooler Leak?
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
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When Issues Typically Appear
Air Suspension Failure (W212)
60K-120K
OM642 Diesel Oil Cooler Leak
60K-120K
Crankshaft Position Sensor Failure
60K-120K
038K75K113K150K mi
Community reported
1,700 owners
On the 2007-2014 Mercedes-Benz E-Class, the OM642 3.0L V6 diesel engine oil cooler seals fail, causing engine oil to leak into the coolant or vice versa. The oil cooler is sandwiched between the engine block and the intake manifold, making access difficult.
Replace the oil cooler seals and gaskets. Requires intake manifold removal for access. Flush both the oil and cooling systems thoroughly after repair to remove cross-contamination.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
Elring 524.281 OM642 oil-cooler seal and intake gasket kit
OEMElring 524.281
Complete disturbed-seal/gasket branch after an OM642 oil-cooler seal leak is positively traced Fitment/availability: The inspected direct page identifies Elring 524.281 with two updated purple oil-cooler seals and the necessary intake-ma…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
WarningDo not drive with oil/coolant mixing. Even brief contamination can destroy bearings and overheat the engine. Tow the vehicle to a shop if you see milky oil.
High Confidence1,700 owner reportsLast reported by owners Mar 2025Reviewed Mar 2026
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.
Loud metallic rattle for 1-3 seconds on cold start
Rattle worse after the car sits overnight or several days
Check engine light
Rough idle when cold
Reduced power / limp mode in advanced cases
Noise diminishes once oil pressure builds
How to Fix
Replace the camshaft adjusters — all four, not just the noisy bank — with the updated Mercedes parts, along with the camshaft adjuster magnets/solenoids. Inspect the timing chain, tensioner and guide rails while the front cover is open and replace them if the chain shows stretch, since a worn chain will destroy new adjusters. The engine must be re-timed and the adaptations reset. Use only the specified MB 229.5/229.51 oil at the correct viscosity and keep to shorter oil-change intervals, as degraded oil accelerates adjuster wear.
On the 2007-2015 Mercedes-Benz E-Class OM642, on the OM642 V6 diesel used in the E320 CDI/BlueTEC and E350 BlueTEC, the swirl-flap actuator motor sits low on the intake and is directly under the turbo intake seal, which is itself a known oil-leak point. Oil drips onto the motor and kills it, and the plastic linkage arm between the motor and the flap shaft snaps. At the same time EGR soot builds up in the intake runners until the flaps physically seize. The result is P2004-P2007 / P2015-type intake runner faults, limp mode capping the engine around 3000 rpm, rough idle and poor throttle response. Owners on BenzWorld and MBClub consistently report that replacing the actuator motor alone without cleaning the intake results in a repeat failure within 20,000-40,000 miles.
Check engine light with intake runner control codes
Rough idle and poor throttle response
Black smoke under acceleration
Oil residue around the intake actuator motor
How to Fix
Remove the intake manifolds and physically clean the soot from the runners and flaps, replace the swirl flap actuator motor and the linkage rod (aftermarket metal rod kits are common and hold up better than the plastic original), and critically, fix the turbo intake seal / oil leak above it or the new motor will be soaked again. Some owners in high-mileage cars go to a swirl-flap delete, but that is not emissions-legal in the US. Address the EGR cooler and intake condition at the same time since the manifolds are already off.
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.
Replace the crankshaft position sensor. A straightforward repair — the sensor is accessible from under the vehicle near the transmission bellhousing. Use OEM or Bosch sensor for reliability.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
Genuine Mercedes-Benz crankshaft position sensor 276-905-14-00
OEMMercedes-Benz 276-905-14-00
M276/M278 E-Class crank-sensor branch after a missing/invalid crank signal and sound circuit confirm failure Fitment/availability: The inspected direct product page identifies genuine 276-905-14-00, superseded numbers, $48 and Add to Cart.
High Confidence1,300 owner reportsLast reported by owners Aug 2025Reviewed Mar 2026
On the 2012-2016 Mercedes-Benz E-Class M276, the M276 3.5L V6 in the W212 E350 uses a three-chain drive with hydraulic tensioners on each chain. When the car sits overnight, oil drains back out of the tensioner bores, so on the next cold start the tensioners take a second or two to pump up and the chains slap against the guides. Owners describe a distinct 1-3 second rattle/marbles noise on cold start that goes quiet once oil pressure builds. Mercedes addressed this with service information LI05.10-P-056435, whose remedy is to install oil check valves (anti-drain-back valves) along with updated chain tensioners so the tensioners stay charged when the engine is off. Left alone, a chronically slack chain accelerates wear on the guides, sprockets and the variable camshaft adjusters, which turns a cheap fix into a front-cover-off job. Note this is a different failure mode from the older M272 balance-shaft gear problem - the M276 chain itself is usually fine.
Loud rattling or 'marbles in a can' noise for 1-3 seconds on cold start
Noise disappears once oil pressure builds
Rattle worse after the car sits overnight or for several days
Occasional timing-correlation check engine light in later stages
How to Fix
Have a shop confirm the noise is chain rattle (not a lifter or belt tensioner) and check for timing-correlation codes. Perform the Mercedes remedy: install the updated hydraulic chain tensioners plus the oil check valves per LI05.10-P-056435. If the noise has been present for a long time, inspect the chain guides, sprockets and camshaft adjusters for wear before just replacing tensioners. Using the correct low-ash MB 229.5/229.51 oil and not stretching oil-change intervals reduces the chance of the tensioners sticking.
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.
Oil visible in or dripping from the camshaft sensor connector
Rough idle, misfires, lack of power
Check engine light with camshaft position/correlation codes
Intermittent stalling or no-start
Oil residue around the timing cover and cam magnets
How to Fix
At the first sign of oil at a cam sensor or adjuster solenoid connector, replace the sensor/solenoid with new O-rings and clean the connector cavity with electrical contact cleaner. Install sacrificial adapter 'pigtail' harnesses between each camshaft adjuster solenoid and the main harness so any future oil migration ruins a cheap pigtail instead of the main harness. Address the underlying timing-cover / cam-cover seepage. If oil has already reached the harness trunk or ECU, the harness section and ECU must be replaced - this is why owners describe five-figure bills when it is ignored.
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.
Common Symptoms
Steering wheel stays locked
Car does not crank / no start
Key must be inserted several times before the steering releases
Clicking noise from the steering column at key insertion
Intermittent no-start that becomes permanent
How to Fix
Diagnose with XENTRY to confirm the ESL is failing to report unlocked rather than an EIS or key fault. Options are: a mail-in ESL repair (motor and gear replaced, original data retained), a new ESL that a dealer or locksmith personalizes to the car's EIS and key, or an ESL emulator (bypass module) - the emulator is the cheapest route but permanently removes the steering lock function. Do not delay once the intermittent hard-unlock symptom appears; it strands cars without warning.
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. This supports the frozen general freeze identity but not the stored hard-drive-failure mechanism, reset-button shortcut or refurbished-unit recommendation.
bulletin software procedure completed before replacement
How to Fix
Record the exact COMAND symptom and software version and follow LI82.85-P-055695: a qualified technician may perform the specified circuit-30 interruption and software update. Do not buy or replace the COMAND unit, hard drive or display from this page; the bulletin specifically directs software repair rather than unit replacement.
Medium ConfidenceVerifiedLast reported by owners Jun 2025Reviewed Aug 2026
Community reported
2,100 owners
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.
Replace the leaking air spring(s). If the compressor runs excessively, replace it as well along with the relay. Arnott and Bilstein make quality aftermarket air springs at lower cost than OEM.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
Arnott A-2790 rear-right W212 air spring
OEMArnott A-2790
W212 rear-right air-spring leak branch, installed with the paired A-2791 left spring Fitment/availability: The inspected direct product page identifies A-2790 for the right rear of 2010-2016 W212 and 2012-2017 W218 applications, with cod…
W212 rear-left air-spring leak branch, installed with the paired A-2790 right spring Fitment/availability: The inspected direct product page identifies A-2791 as the paired left rear spring for W212/W218 code 488/489 applications and sho…
High Confidence2,100 owner reportsLast reported by owners Sep 2025Reviewed Mar 2026
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.
"AdBlue: X starts remaining" or remaining-distance countdown message
Check engine light
Warning appears despite a full AdBlue tank
Reduced power / limp mode
Engine will not restart once the countdown reaches zero
AdBlue consumption higher than expected
How to Fix
Read the fault memory before assuming the AdBlue tank or pump is at fault — a full tank with a countdown almost always points at a NOx sensor or the SCR catalyst efficiency monitor, not at the fluid. Replace the failed NOx sensor, usually the downstream unit, with a genuine part; aftermarket NOx sensors on these cars are widely reported to fail again or not match the ECU calibration. Check for exhaust leaks upstream of the sensor and for urea crystallization in the injector and the SCR inlet, and inspect the AdBlue heater and level sender while you are there. After the repair the countdown must be cleared with a Mercedes-capable scan tool; it will not clear itself. Do not let the count run down — once it reaches zero the car requires a tow, and always use only certified AdBlue/DEF, since contaminated or off-spec fluid poisons the catalyst and causes a much more expensive repeat failure.
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.
Common Symptoms
Wet driver or passenger footwell after rain
Water dripping from the A-pillar trim or headliner
Damp or stained headliner near the roof opening
Musty smell in the cabin
Water pooling under the seats or in the rear footwell
Unexplained electrical faults after wet weather
How to Fix
Locate the drain outlets (the front pair are inside the front wheel liners) and flush them - a length of clear vinyl tubing or a small flexible hose with low-pressure water is the method owners use; do not push stiff wire down the tube, it splits the hose. Clean the sunroof cassette tray and check that the drain nipples have not popped off. Then pull the sill plates, kick panels and carpet, dry the floor pan and the sound deadening completely, and inspect any modules or connectors that sat in water. Make clearing the drains an annual maintenance item, especially if the car parks under trees.
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.
Common Symptoms
Wet or damp front or rear floor carpet
Musty or mildew smell from the interior
Water dripping from the headliner or A-pillar during rain or a car wash
Water audible sloshing in the pillars
Fogged windows that will not clear
Unrelated electrical faults after heavy rain
How to Fix
Clean the drains rather than resealing the glass. Open the roof, vacuum the tray corners, and clear each of the four tubes with low-pressure compressed air or a length of soft trimmer line fed gently from the top — high pressure or stiff wire will blow a tube off its nipple inside the pillar and turn a cheap job into a trim-removal job. Verify flow by pouring water into each tray corner and watching for it to exit behind the wheel arch. If drains flow but the car still leaks, pull the A-pillar trim and check that the drain hose is still attached to the tray nipple and that the tray seal is intact. Dry the carpet and jute padding completely, and inspect any footwell connectors and modules for corrosion. Clean the drains annually, more often if the car parks under trees.
The OM642 3.0L V6 diesel engine oil cooler seals fail, causing engine oil to leak into the coolant or vice versa. The oil cooler is sandwiched between the engine block and the intake manifold, making access difficult. Repairs typically run $800-$2,500. Severity: high.
What is the 2006-2016 Mercedes-Benz E-Class Camshaft Adjuster Solenoid / Position Sensor Oil Wicking into the Engine Harness and ECU?
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 in… Repairs typically run $250-$4,000. Severity: high.
What is the 2012-2016 Mercedes-Benz E-Class M276 V6 Camshaft Adjuster (VVT Phaser) Wear Causing Cold-Start Rattle and Cam/Crank Correlation Faults?
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… Repairs typically run $1,500-$4,000. Severity: high.
What is the 2007-2015 Mercedes-Benz E-Class OM642 Diesel Intake Swirl-Flap Actuator Motor (M55) Failure and Carbon-Clogged Intake Runners Causing Limp Mode?
On the OM642 V6 diesel used in the E320 CDI/BlueTEC and E350 BlueTEC, the swirl-flap actuator motor sits low on the intake and is directly under the turbo intake seal, which is itself a known oil-leak point. Oil drips onto the motor and kills it, and the plastic linkage arm betwe… Repairs typically run $600-$2,500. Severity: high.
What is the 2010-2014 Mercedes-Benz E-Class Electronic Steering Lock (ESL/ELV) Motor Failure Causing Steering Locked and No-Crank?
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 pat… Repairs typically run $300-$1,500. Severity: high.
What is the 2011-2016 Mercedes-Benz E-Class NOx Sensor Failure in the SCR/AdBlue System Triggering a Start-Prevention Countdown?
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-cry… Repairs typically run $600-$1,800. Severity: high.
What is the 2010-2018 Mercedes-Benz E-Class Crankshaft Position Sensor Failure?
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. Repairs typically run $100-$350. Severity: medium.
What is the 2003-2016 Mercedes-Benz E-Class Sunroof / Panoramic Roof Drain Blockage Flooding the Footwells and A-Pillar Trim?
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… Repairs typically run $150-$1,200. Severity: medium.
What is the 2012-2016 Mercedes-Benz E-Class M276 V6 Hydraulic Timing Chain Tensioner Drain-Down Causing Loud Cold-Start Chain Rattle?
The M276 3.5L V6 in the W212 E350 uses a three-chain drive with hydraulic tensioners on each chain. When the car sits overnight, oil drains back out of the tensioner bores, so on the next cold start the tensioners take a second or two to pump up and the chains slap against the gu… Repairs typically run $700-$2,200. Severity: medium.
What is the 2010-2016 Mercedes-Benz E-Class Panoramic Sunroof Drain Tube Clogging Causing Water Intrusion into Cabin and Footwell Electronics?
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… Repairs typically run $150-$900. Severity: medium.
What is the 2010-2016 Mercedes-Benz E-Class COMAND Infotainment System Freeze?
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 un… Severity: low.
