Mercedes-Benz AMG C 63
The M177 is AMG's most widely used V8 biturbo today and is considered technically mature and long-lived. The hot-V turbocharger arrangement delivers spontaneous response with barely perceptible lag. Weaknesses are manageable: wastegate rattle in cold weather, ignition coil recall for early 2015 model years, valve cover gaskets with age. Regular oil changes with attention to oil quality deliver a very robust engine. In direct comparison with the M156 less emotional, but significantly more reliable and efficient.
476 hp RWD — the purest way to feel the M177
The lightest M177 in the lineup and the only one without all-wheel drive. In the wet it gets interesting — anyone giving it full throttle on wet tarmac ends up sideways. That's exactly the appeal. Sound with exhaust valve: deep, punchy, drowning out every M3. Without the valve control almost too quiet inside. Standard seats have insufficient lateral support — performance seats essential. 15 L/100 km realistic, up to 22 L in town. COMAND infotainment (pre-2018) dreadful.
Engine Weaknesses 8
The MCT Speedshift gearbox (wet launch clutch instead of torque converter) wears the clutch significantly faster in frequent stop-and-go. Clutch replacement requires gearbox removal.
Symptoms: Judder on pull-away, clutch slip at full load, gearbox warning message, delayed engagement from standstill
Identical issue to the M176/M278: the solenoid leaks, oil migrates by capillary action through the wiring harness. On AMG vehicles this is even more frequent due to higher oil temperatures.
Symptoms: Cold-start rattle, camshaft adjuster fault code, oil traces on connector, potential ECU consequential damage
The camshaft cover gaskets on the M177 AMG V8 become brittle from the high heat exposure in the hot-V. Oil escapes onto turbochargers and exhaust system.
Symptoms: Oil smell on hot engine, oil film on turbochargers, smoke from engine bay
The M177 has several electric auxiliary coolant pumps for charge air cooling. These fail and lead to elevated charge air temperatures with power reduction.
Symptoms: Power reduction during spirited driving, cooling system fault codes, elevated charge air temperature
The camshaft adjuster solenoids on the M177 can leak internally or stick. Fault codes for camshaft position and rough running are the result.
Symptoms: Check engine light, rough idle, camshaft position fault codes, power loss in the lower rev range
Vehicles with M177/M178 engines built between Jan. and Nov. 2015 had faulty ignition coils that caused misfires. Mercedes replaced affected parts under a recall.
Symptoms: Rough idle, misfires, check engine light, occasional limp mode
The wastegate flaps of the BiTurbo system clatter briefly after cold start. Normally disappears after a few seconds. With prolonged operation replace the wastegate actuator.
Symptoms: Metallic clattering directly after cold start, disappears after warm-up, permanent with wear
As a direct-injection engine without port injection, carbon residues build up on the intake valves. Walnut blasting every 50,000–80,000 km recommended. Performance loss is gradual.
Symptoms: Gradually roughening idle, slight power loss, elevated fuel consumption
Vehicle Weaknesses 7
Longitudinal members, jack-point attachment holes and rear axle subframe rust through. MB offers goodwill replacement.
Polycarbonate blind cover of the panoramic roof incorrectly bonded. When opening, the blind can come loose. Recalled by MB.
Ball joints on the wheel-side wishbone and rubber-metal bushes wear. New suspension geometry makes repairs more involved.
Some W205 models discharge the battery unusually quickly during extended parking. Cause: elevated quiescent current draw from control units.
The W205 shows above-average front axle issues from the second MOT onwards according to TÜV statistics. Worn control arms and drop links are the main causes.
W205 A/C fails with 'Air conditioning off' without a fault code in the onboard computer. Often the compressor or A/C control unit is defective.
Panoramic roof on the W205 creaks when opening and closing. Guide linkage can bend and jam the roof. Repair often requires complete removal.