The 2024 S63 AMG uses Mercedes' M177 4.0L twin-turbo V8 paired with a hybrid system and the AMG Speedshift MCT 9-speed. Early data shows catastrophic bearing failures and turbo-related issues reminiscent of older M177 problems, despite claimed improvements.
Connecting Rod and Main Bearing Failures
Occasional · high severity
Typical onset: 30,000-60,000 mi
Symptoms: Sudden knocking or ticking from deep in engine block, Metallic debris in oil during analysis, Check engine light with multiple misfire codes, Loss of power under acceleration, Eventually catastrophic engine seizure
Fix: Complete engine teardown required. Most shops recommend short block replacement or full engine rebuild. Expect 25-35 labor hours for short block swap, 40-50 hours for full rebuild with machine work. Root cause often traced to oil starvation during aggressive driving or extended oil change intervals.
Estimated cost: $18,000-32,000
Turbocharger Hot-Side Failures
Occasional · high severity
Typical onset: 40,000-70,000 mi
Symptoms: Blue smoke on cold starts or hard acceleration, Loud whistling or grinding noise from engine bay, Severe loss of boost pressure, Oil consumption increases dramatically, P0299 turbo underboost code
Fix: Hot-V configuration makes this a nightmare. Must remove intake manifold, valley cover, and deal with integrated exhaust manifolds. Turbos themselves are $3,500-4,500 each from Mercedes. Plan 18-22 hours labor for both turbos, less if only one side fails. Often find heat-damaged oil feed lines during replacement.
Estimated cost: $12,000-18,000
Transmission Oil Cooler Line Leaks
Common · medium severity
Typical onset: 20,000-50,000 mi
Symptoms: Transmission fluid puddles under vehicle, usually passenger side, Low transmission fluid warnings on dash, Rough or delayed shifts when fluid level drops, Pink fluid visible near front subframe area
Fix: Quick disconnects and plastic fittings crack from heat cycling and road debris. Cooler lines run along subframe and are exposed. Access is tight but doable without dropping subframe on lift. Replace both lines and fittings as preventive measure. 3-4 hours labor plus transmission fluid refill and adaptation procedure.
Estimated cost: $800-1,400
Hybrid Battery Cooling System Failures
Occasional · high severity
Symptoms: Hybrid system fault messages, Vehicle enters limp mode, ICE-only operation, Reduced power output significantly, Battery temperature warnings, No electric-only driving capability
Fix: The 48V hybrid system has dedicated cooling circuit. Pumps fail or coolant leaks develop in battery pack area. Diagnosis requires Mercedes Star system. Battery pack removal necessary for some repairs - 8-12 hours labor. Cooling pump replacements are 4-6 hours. Parts availability is problematic with many on national backorder.
Estimated cost: $3,500-8,500
Piston Ring Wear and Blow-by
Occasional · high severity
Typical onset: 50,000-80,000 mi
Symptoms: Excessive oil consumption, 1+ quart between services, Blue smoke from exhaust under load, Loss of compression on cylinder leakdown test, Carbon buildup visible in intake from PCV system, Reduced power and fuel economy
Fix: M177 engines run hot and ring land temperatures can exceed design limits during sustained high load. Rings lose tension and allow combustion gases past. Requires complete top-end rebuild minimum - heads off, hone cylinders, new rings and gaskets. If cylinder wear is present, needs full short block. 30-40 hours labor for proper rebuild with ridge reaming and deck surfacing.
Estimated cost: $15,000-25,000
Engine and Transmission Mount Failures
Common · low severity
Typical onset: 35,000-65,000 mi
Symptoms: Clunking when shifting from park to drive, Excessive vibration at idle in drive, Visible sagging of engine or transmission on visual inspection, Harsh engagement during aggressive launches
Fix: Hydraulic mounts can't handle the torque from this powertrain, especially with hybrid boost added. Transmission mount is worst - usually tears internally. Engine mounts follow. Replace all mounts as a set for best results. Transmission mount alone is 2-3 hours, all mounts together 5-7 hours. Requires supporting powertrain properly.
Estimated cost: $1,800-3,200
Owner tips
Use only Mercedes 229.71 spec oil and change every 5,000 miles maximum - bearing failures correlate strongly with extended intervals
Install oil catch can on PCV system to reduce carbon buildup in intake and on valves
Transmission fluid change every 40,000 miles despite 'lifetime fill' claim - MCT units are sensitive to degraded fluid
Avoid sustained full-throttle pulls longer than 15-20 seconds until oil temperature exceeds 200°F
Budget $3,000-5,000 annually for repairs after warranty expires - these are not Toyota-reliable
Avoid unless you have a comprehensive warranty or $10k+/year maintenance budget - the M177 hybrid platform has serious durability issues that Mercedes hasn't fully resolved, even in 2024.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: Located in trunk; AGM required for start-stop and hybrid system; high-performance application requires premium AGM battery
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Every control module on the 2024-2026 Mercedes-Benz S63 AMG — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Rear Axle Steering Control Unit (RAS)2.5 hr R&Rsecurity gateway +1.5 hr▸ programming details
📍 Rear axle, center mounted
🔧 Xentry Diagnostics + SCN online
⚠️ Rear-wheel steering system. Requires extensive calibration and alignment after replacement.
Transmission Control Unit (TCU)2.5 hr R&Rsecurity gateway +1.0 hr▸ programming details
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2024 Mercedes-Benz S63 AMG 4.0L V8 BiTurbo Hybrid M177 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.