Mercedes-Benz S 600
Development of the M275 with increased displacement. Exclusive V12 for S 600 and Maybach. Identical weaknesses to M275, spare parts very expensive.
Powerfully Motorised
390 kW — sovereign progress with reserves.
Engine Weaknesses 6
Despite a revised design, the fully potted ignition module banks are wear items. Failures can be expected from around 100,000–150,000 km or after 10+ years.
Symptoms: Misfire codes P0307–P0312, rough running, power loss, check engine light
At high mileage the turbocharger bearings wear; oil enters the intake tract. Engine removal needed for turbo replacement.
Symptoms: Whistling or rattling noises, blue-white smoke, declining power, P0299 fault code
The M277 is paired with the ABC active suspension. The high-pressure hydraulic lines age and develop leaks. Hydraulic fluid drips onto the hot exhaust — fire hazard.
Symptoms: Dropping ABC fluid level, oil puddles under vehicle, ABC warning message, suspension sinks on one side
Identical issue to the M275: 4 solenoids on the V12 develop leaks. Oil creeps into the wiring harness and corrodes control units. Mercedes has oil stop rings as a retrofit solution.
Symptoms: Cold-start rattling on both cylinder banks, camshaft adjuster fault codes, oil film on wiring connectors
The oil-water heat exchanger in the V-valley becomes leaky over time. Access only through extensive engine disassembly. According to forums, inevitable sooner or later.
Symptoms: Slow oil loss, oil spots under the vehicle without visible external leak
The M277 V12 Biturbo has two separate cooling circuits (bank 1+2). Both thermostats and water pumps can fail independently. Diagnosis without the Star diagnostic system is difficult.
Symptoms: Temperature gauge fluctuates, one cylinder bank overheats, different exhaust temperatures left/right, coolant loss
Vehicle Weaknesses 14
The active electro-hydraulic ABC suspension requires intensive maintenance. Hydraulic lines, valve blocks and pumps can develop leaks. Hydraulic oil change required every 50,000 km.
Air bags and pressure hoses develop leaks. The compressor runs continuously and overheats. Repair: air bag pair 2,500–3,500 €, compressor 1,000–1,300 €.
Air struts on Airmatic and Magic Body Control suspensions develop leaks. Vehicle drops, suspension warning light appears. Repair per corner is very costly.
The hydraulic Magic Body Control suspension is prone to valve block and hydraulic pump failures. Contamination in the oil causes system failures.
The COMAND infotainment system freezes sporadically or fails completely. System faults increase from around 100,000 km.
Radar and camera sensors for adaptive cruise control and emergency braking can cause malfunctions due to dirt or defects. Calibration after repair is expensive.
The COMAND navigation system shows read errors, freezes or fails to boot. A defective drive unit is the most common cause.
Matrix LED headlights are not repairable -- individual modules cannot be replaced. Moisture and electronic failures require complete headlight replacement.
Window regulators fail or become unresponsive. Cause is often a software fault in the door control unit, fixable by update.
Brake discs and pads wear quickly due to the high vehicle weight. Particularly during spirited driving.
The pneumatic control unit operates soft-close, central locking and rear headrests via a shared pump. Leaks cause all functions to fail simultaneously.
The Comand NTG5 infotainment system shows display failures, freezing and navigation start errors. Temperature-dependent malfunctions occur frequently.
Seat heating mats and massage pneumatics in the multicontour seats are wear items. Heating mats fail internally, the PSE pump loses pressure for the massage function.
The rubber seal of the Keyless Go microswitch in door handles becomes brittle through UV and temperature cycling. Moisture enters, the switch corrodes.
Reports & Tests
187 owner complaints filed with NHTSA (2013–2020). Most reported: Other (43), Steering (22), Engine (20).