Mercedes-Benz E 500
Large-displacement naturally aspirated V8, second generation with variable valve timing on all four camshafts. Technically related to the M272 V6 — shares its known balance shaft sprocket problem on build years before 2007 (engine number below 088611). From that number the sprocket was made of hardened steel. Check early engines for fault codes P0016/P0017 and cold-start chain noise. The 5.5-litre with 285 kW is the typical variant; the 5.0-litre with 225–250 kW is somewhat more forgiving in heavier vehicles. The M278 BiTurbo successor is more efficient and more powerful, but sounds considerably less characterful — the M273 is the last true naturally aspirated V8 from Stuttgart. Pre-purchase: always check for camshaft adjuster leaks (oil in wiring harness) and thermostat fault P0128. Oil changes every 10,000 km with MB 229.5.
E 500 W212 — Cultured and Almost Too Quiet
The W212 suppresses the M273 acoustically so effectively that V8 feel only arrives with the window open. Power delivery linear and sovereign, but internally the engine sounds like a well-insulated inline-six. As a quiet long-distance machine with reserves it's barely equalled — those wanting sound open the window or step up to the W211. Fuel consumption 11–13 litres on the motorway.
Engine Weaknesses 9
The M273 V8 shares the balance shaft sprocket issue with the M272 V6. The soft composite material of the sprocket wears down, causing timing chain rattle.
Symptoms: Fault codes P0016/P0017, chain rattling, rough idle, power loss
As with the similarly-designed M272, the solenoid valves leak. The V8 has 4 per bank — consequential costs are particularly high due to more solenoids. Oil migrates by capillary action all the way to the ECU.
Symptoms: Check engine light with camshaft fault codes P0014/P0015/P0021/P0025, lambda sensor failures, in extreme cases ECU failure
Like the M113, the valve cover gaskets on the M273 V8 become porous over time. With a V8 having two cylinder heads, the workload doubles.
Symptoms: Oil spots under the vehicle, oil smell after hard driving, oily engine bay
Identical to the M272: plastic linkages on the variable intake flaps become brittle and break. Fault code P2006 is typical.
Symptoms: Check engine light with P2004–P2006, minimal power loss at certain rpm
The 3-disc thermostat on the M273 V8 fails prematurely in the open position. On motorway driving coolant temperature drops to 75–86°C. Difficult to access in the V8 engine bay.
Symptoms: Coolant temperature fluctuates between 75–102°C depending on load, engine does not reach operating temperature in cold conditions, fault code P0128
The M273 V8 frequently shows sporadic misfires from aged ignition coils. Water in the plug well through porous seals accelerates failure.
Symptoms: Hesitation on acceleration, rough engine running, fault codes P0301–P0308, check engine light flashes with heavy misfires
As mileage increases the M273 V8 shows noticeable oil consumption. 32 valve stem seals wear simultaneously. Above approx. 0.5 L/1,000 km intervention is needed. When doing the balance shaft repair, renew seals and rings at the same time.
Symptoms: Blue smoke on cold start or after long overrun phases, dropping oil level between service intervals, oil consumption above 0.5 L/1,000 km
The throttle body is prone to heavy carbon buildup from approx. 120,000 km. Idle hesitates and vibrates, throttle response lags on load changes. Cleaning is possible but requires a basic adaptation with a diagnostic tool.
Symptoms: Rough idle at operating temperature, slight hesitation on pull-away, engine revs unevenly after cold start, occasional stalling
Engine mounts fatigue and no longer adequately dampen V8 vibrations. Noticeable vibrations in the interior and at the steering wheel around 1,800 and 2,400 rpm. Test: blip the throttle at idle — more than 4 cm of engine movement indicates mounts are due.
Symptoms: Noticeable vibrations at 1,800 and 2,400 rpm, dull droning in the passenger compartment, visible engine rocking when blipping the throttle at idle
Vehicle Weaknesses 13
Rear subframe rusts from the inside out. Faulty factory sealant allows water ingress. Flagged as safety-critical at MOT.
W212 steel rear subframe with powder coating cracks over time and allows moisture in. Rusts from the inside. Mercedes replaces as a goodwill gesture. Safety-critical.
Brake lines above the rear axle corrode through after 8–10 years. Brake fluid loss leads to brake failure. MOT refusal.
Rear axle corrodes through with age; suspension mounting points are flagged at MOT. Goodwill repairs possible but time-limited.
Brake lines corrode at two to twelve times the rate of comparable vehicles according to MOT data.
The rear axle is prone to severe rust-through from the inside at the weld seams of the subframe. The problem goes unnoticed for a long time. Mercedes granted goodwill replacements in some cases.
Worn joints and strut rod ends on the front axle are a recurring problem. Classic wear pattern at higher mileages.
Drain holes in the sills clog up; water collects and promotes rust from the inside.
Worn ball joints and strut top mounts on the front axle are a recurring problem. Individual owners reported multiple repairs.
The soft top tends to develop cracks in the fabric after about 10 years. Ignored cracks lead to water ingress, mould growth and control unit damage.
The drain channels in the sills clog regularly, causing water accumulation and corrosion in the sill area. Control units in the floor area can become damp.
Knocking and rattling from the front axle on uneven road surfaces. Causes: worn ball joints, anti-roll bar bushings.
The parking brake is regularly flagged at MOT. Corrosion from infrequent use causes it to seize or fail.