Mercedes-Benz AMG C 63 S E Performance
Two-litre turbo with 350 kW, electrically assisted exhaust turbocharger, 150 kW electric motor on the rear axle โ 500 kW system output. Barely audible at idle, often running on electricity alone. At full throttle a hoarse four-cylinder howl that doesn't satisfy the ears no matter how fast the needle rises. The electric turbo eliminates every trace of turbo lag; boost is immediate. 6.1 kWh battery in immersion cooling (14 litres of coolant flow directly through the cells). On paper a masterpiece: 2,165 kg in 3.4 seconds to 100, 280 km/h top speed. In practice a dilemma โ the target audience wanted V8 sound and emotion, got 2.1 tonnes of high-voltage complexity. AMG chief Schiebe publicly admitted: customers were lost. Consequence: the CLE 63 gets a V8 back, the C63 successor will be the C53 with an inline-six. Maintenance is AMG-level: oil every 10,000 km (MB229.51, 7 litres), HV system only in certified workshops.
680 hp Wrong Turn โ Commercial Accident
500 kW system output, 2,165 kg, fake exhaust tips, no V8 sound โ โฌ120,000 starting price. A technical masterpiece that nobody ordered. UK: 13 new registrations, Germany: orders near zero, 20% dealer discount on new cars. 35% depreciation in under two years. Brutally fast in a straight line, emotionally nothing. A fascinating depreciation disaster that history will remember as a brave wrong turn.
Engine Weaknesses 12
Affected MY 2022โ2023 AMG C43: incorrectly-length gearbox wiring harness fitted, can cause loss of drive.
Symptoms: Warning in instrument cluster, sudden loss of drive, possible short circuit.
MY 2023โ2024: Incorrectly manufactured 80A fuses in the main fuse box can fail and cause total electrical system failure. Free replacement at the dealer.
Symptoms: Sporadic electrical failures, warnings in instrument cluster, in extreme cases complete electronics failure
Software fault in the high-voltage starter-generator control unit can cause loss of drive. Affects several AMG E Performance models. Free software update at the dealer.
Symptoms: Sudden loss of drive, hybrid drivetrain warning, vehicle unable to pull away
Insulation resistance between HV circuit and vehicle earth drops below 250 kฮฉ (target: >1 Mฮฉ). BMS locks HV relays, vehicle no longer starts. Requires OEM battery replacement.
Symptoms: Vehicle does not start, no visible fault message initially, after diagnosis: BMS lockout due to insulation fault
The electric exhaust turbocharger is powered via the 48V network. Individual cases document check engine lights. E-turbo is a unit with a 6 kW electric motor.
Symptoms: Check engine light, reduced engine power, turbo lag despite electric assist.
The 8G-DCT dual-clutch gearbox on the M139 shows occasionally erratic shift behaviour and sporadic fault messages. Rev-hanging on upshifts and rough transitions in city traffic.
Symptoms: Shifting at too-high revs, rough or delayed gear changes at low revs, occasional gearbox warning lights after spirited driving
The M139L is thermally extremely stressed (421 hp / 2.0 L). Sustained sporty use increases the risk of coolant loss and thermal management problems. Power reduction via protective programme.
Symptoms: Temperature gauge rises above normal range during spirited driving, coolant warning message, power reduction via thermal protection programme after track use
The twin-scroll turbocharger is optimised for 421 hp. With regular track use or improper cold-start behaviour it can wear prematurely. Oil supply after shutdown is critical.
Symptoms: Whistling from turbo area, power loss at high revs, blue smoke at cold start, rising oil consumption
The standard steel brakes are marginal for 2,165 kg at 500 kW system output. After repeated heavy braking performance noticeably drops off. Ceramic option available as upgrade.
Symptoms: Fading braking effect after several hard stops, brake disc discolouration, extended braking distance
Under repeated high-load stress (track use) thermal management reduces electric motor output. A design-related protection function.
Symptoms: Power reduction after several full-throttle laps, thermal management warning
The 12V battery repeatedly triggers low-voltage alarms. Door control units and comfort electronics are affected. Most frequently reported problem according to purchasing advisors.
Symptoms: Warning on display for low battery voltage, sporadic failures of door locking and comfort functions, fault memory entries
The M139L shows elevated oil consumption under high-load operation. Oil capacity 7.0 litres; nevertheless check oil level regularly between services. Increased with track use.
Symptoms: Dropping oil level between service intervals, slight oil smell on hot engine, oil level warning
Vehicle Weaknesses 7
Early W206 models with documented brake defects. The model is relatively young; extent still unclear.
Defective wiring harness to the engine control unit can damage the fuel line. Approximately 101,445 vehicles affected worldwide. KBA ref. 012144.
Defectively secured fuel line can lead to fuel entering the passenger compartment. Approximately 28,783 vehicles affected worldwide.
Sporadic failures of ESP, emergency stop assistant, lane-keeping assist and cruise control. Cause often a ground cable misrouted at the factory.
MBUX system shows crashes, restarts and connectivity problems. Software updates are regularly rolled out but do not fix all cases.
MBUX infotainment system freezes or restarts, especially on long journeys. Early production runs up to mid-2023 more frequently affected.
Rumbling front axle at low speeds and over road bumps. Classified as normal production characteristic by Mercedes.