A refined luxury sedan with impressive performance from the twin-turbo V8. The W212 facelift (2013+) brings significant improvements over pre-facelift models including better build quality, enhanced safety features, and resolved rear subframe corrosion issues that plagued earlier production. The M278 engine is generally reliable but has known timing chain tensioner concerns on early builds and requires vigilant oil monitoring. Airmatic suspension is durable but expensive when it fails. Main concerns center on timing chain rattle on cold starts, oil consumption, turbocharger actuator sticking, and battery drain from parasitic electrical draws. Budget for premium fuel and high service costs.
Tensioners lose pressure causing cold start rattle for 1-30 seconds · more· less
Early build M278 V8s have problems with timing chain tensioners causing a distinctive metallic rattle on startup. The tensioner's check valve weakens over time, allowing oil pressure to bleed off overnight. Typically occurs between 60,000-100,000 km. Engine numbers ending in 30 191844 or higher have enhanced tensioners. The M278 has a complicated chain drive with one primary chain and two secondary chains, each with its own tensioner (3 total). Replacement costs €2,000-3,000 for tensioners alone, but mechanics recommend replacing chains, guides, and sprockets simultaneously to avoid paying for labor twice, bringing total cost to €4,000-5,500. Ignoring the rattle risks chain skip and catastrophic valve/piston contact.
Air struts develop leaks, compressor fails from overwork · more· less
The W212's Airmatic system is improved over earlier generations but still prone to failures. The rubber bladder in air struts becomes brittle and cracks over time, typically after 80,000-150,000 km. Front struts cost €700-900 each (aftermarket Arnott), rear air springs €200-300 each, rear shocks €500 each (OEM). Compressor replacement adds €500-800. Dealer quotes for a single corner repair run €2,000+. The problem: rear bags are inexpensive but labor-intensive to replace, while front struts are easy to change but expensive. If leaks aren't addressed quickly, the compressor runs continuously and fails prematurely. Symptoms include sagging suspension, uneven ride height, "Visit Workshop" warnings, or rough ride quality.
Oil consumption and oil leaks€400 - €1,500
High oil consumption from worn rings/seals, leaks from valve covers and timing covers · more· less
The M278 engine commonly develops oil leaks from valve cover gaskets and timing chain cover seals. Oil consumption of 1 liter per 1,000-2,000 km is frequently reported and often stems from worn piston rings or valve seals. Valve cover gasket replacement costs €600-900 per side. Timing cover seal leaks require more extensive work at €800-1,500. Monitor oil level between services and top up regularly - the car will warn you but running low on oil risks premature bearing wear. Premium 0W-40 synthetic oil costs €80-120 for 8 liters. Budget €100-200 annually for extra oil top-ups if consumption is present.
Turbocharger actuator sticking€500 - €5,500
Carbon buildup causes actuator to stick, triggering limp mode and EPC light · more· less
The M278 uses twin small Honeywell turbochargers with vacuum-controlled wastegate valves. Gentle driving and short trips allow carbon to build up on actuators, causing them to stick. Symptoms include EPC warning light, loss of power, limp mode, and reduced boost pressure. Mercedes won't sell actuators separately. Actuator-only repair at a specialist costs €500-800, but if turbo internals are damaged from excessive temperatures, full turbocharger replacement runs €4,500-5,500 for both turbos at dealers. Using premium fuel and regular spirited driving helps prevent buildup. Turbo coolant lines can also become brittle and crack, requiring replacement.
Battery drain from parasitic draw€200 - €1,200
Battery dies after 3-7 days parked due to malfunctioning modules · more· less
W212 E500 owners frequently report unexpected battery drain. Normal sleep draw is 20-50 mA, but many cars show 100+ mA draws from modules that refuse to sleep. Most common culprits: seat control modules (especially passenger seat circuit), COMAND infotainment system, instrument cluster that powers itself back on, Teleaid module, and stuck relays. Diagnosis requires methodically pulling fuses to identify the circuit. Seat module replacement costs €300-600, COMAND module €800-1,200. Some owners solve this by using a battery tender when parked for more than 3 days. Battery replacement every 4-5 years costs €200-350 for a quality AGM battery.
Engine mount deterioration€800 - €1,500
Worn mounts transmit vibration to steering wheel and cabin at idle · more· less
After 80,000-120,000 km, engine and transmission mounts begin to deteriorate, especially with the heavy V8. Symptoms include noticeable steering wheel vibration at idle, clunking when shifting from Park to Drive, and increased cabin vibration. The W212 has three mounts: two engine mounts and one transmission mount. Replace all three simultaneously as they wear together. OEM mounts cost €250-400 each plus 4-6 hours labor. Aftermarket mounts are cheaper (€100-200 each) but may be stiffer and transmit more vibration. Total replacement cost at independent shops runs €800-1,000, dealers charge €1,200-1,500.
Window regulator failure€320 - €1,400
Plastic components break causing windows to stick or fall into door · more· less
Window regulator failure is common on W212 as plastic components and wire cables wear out. Symptoms include intermittent window operation, grinding/clicking noises, windows stuck halfway, or windows dropping inside the door panel. The W212's inner door panel is riveted to the outer panel and must be removed to replace regulators, requiring significant labor. Dealer quotes run €1,200-1,400 per window. Independent Mercedes specialists charge €600-900. Specialty auto glass shops can do it for €300-450. Aftermarket regulators cost €50-150 on eBay/Amazon, or €250-400 for quality units. DIY is possible if you have a drill and rivet gun (2-3 hours per door).
Rear subframe corrosion€0 - €4,000
Pressed steel subframe rusts from inside, especially on pre-2013 models · more· less
The W212 switched from aluminum (W211) to pressed steel subframes which are prone to internal corrosion, particularly on cars driven in winter climates with road salt. Water and salt enter through an uncovered hole in the front attachment point. The 2013-2014 facelift models have improved corrosion protection and are less affected than 2010-2012 cars. Good news: Mercedes has extended warranty coverage to 20 years/unlimited miles for rear subframes with corrosion perforation (holes). If your authorized Mercedes dealer confirms perforation, inspection and replacement are performed at no cost, regardless of ownership. This applies in Germany, Netherlands, and across Europe under the 30-year non-perforation warranty. Without warranty coverage, replacement costs €3,500-4,000 including alignment. Check under the car carefully during pre-purchase inspection.
Solid luxury sedan, but budget for V8 maintenance
The W212 E500 with M278 engine is significantly more reliable than the previous W211 generation. With proper maintenance and early attention to issues like timing chain rattle, these cars can exceed 200,000 km. The 2013-2014 facelift brings important improvements over earlier W212 models. However, when things break, parts and labor costs are high. Avoid cars with only short-trip history or deferred maintenance. Service history is critical.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete Mercedes dealer or specialist records essential. Look for regular oil changes at proper intervals and timing chain work if mileage is high.
Tires
Check tread depth, age (date codes), and uneven wear patterns. E500 uses staggered setup: 245/40R18 front, 265/35R18 rear.
Cold start test
Must start engine completely cold. Listen carefully for timing chain rattle in first 30 seconds. Brief rattle (1-2 seconds) may be acceptable, prolonged rattle is a red flag.
Test drive
Minimum 30 minutes including highway speeds. Monitor for smooth power delivery, no hesitation, and proper transmission shifts.
Undercarriage inspection
Get car on a lift. Check for oil leaks, rear subframe rust, exhaust condition, and suspension component wear.
Specific for this vehicle
Cold start timing chain rattle test
Start engine completely cold after sitting overnight. Listen for metallic rattle from front of engine. Rattle lasting more than 2-3 seconds indicates worn tensioners requiring €4,000+ repair.
Check engine number for timing chain updates
Engine numbers ending in 30 191844 or higher have enhanced tensioners. Earlier engines are more prone to timing chain issues.
Monitor oil consumption during test drive
Check oil level before and after 50+ km test drive. Some consumption is normal but excessive consumption (1L per 1,000 km) indicates worn rings/seals.
Test Airmatic suspension in all modes
Cycle through comfort/sport modes. Check for "Visit Workshop" warnings. Car should raise/lower smoothly. Listen for compressor running excessively. Visually inspect struts for oil leaks or cracked rubber.
Battery and electrical system test
Check battery voltage (should be 12.6V+ when off). Have dealer or specialist run parasitic draw test to identify any modules not sleeping properly.
Look for oil leaks at valve covers and timing covers
Inspect engine bay with a flashlight. Look for oil seepage around valve covers (top of engine) and timing chain covers (front of engine). These are common leak points.
Inspect rear subframe for rust
On a lift, carefully inspect rear subframe for surface rust, bubbling, or perforation. 2013-2014 facelift models less affected but still check. Mercedes covers replacement if perforated.
Test all windows and listen for regulator noises
Cycle each window up and down multiple times. Listen for grinding, clicking, or struggling. Check for smooth operation without hesitation.
Check for vibration at idle and during driving
Feel steering wheel and seat at idle with engine warm. Excessive vibration indicates worn engine/transmission mounts. Test at various speeds for wheel balance issues.
Recalls and Technical Service Bulletins
Rear subframe corrosion warranty extension20 years/unlimited miles
Timing chain tensioner check valve updateEngine number dependent
Takata airbag inflator recallVerify completed
Contact Mercedes-Benz with VIN to verify all recalls completed and check if your specific car is covered under the rear subframe warranty extension. For 2013-2014 models, also check for any M278 engine-specific TSBs related to timing chain or turbocharger updates.
Warranty Status
Factory warranty (2 years unlimited km)Expired on all 2013-2014 models
Extended warranty availabilityAvailable through dealers or third parties
Rear subframe corrosion warranty20 years/unlimited km if perforated
All 2013-2014 E500s are outside original factory warranty. Extended warranty coverage is available through Mercedes dealers and third-party providers but carefully review coverage exclusions. The rear subframe warranty extension to 20 years/unlimited miles applies regardless of ownership if corrosion perforation is present. In Europe, the 30-year anti-corrosion warranty may apply if service records are complete at authorized Mercedes centers.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.