The 2016 E63 AMG with the M157 5.5L BiTurbo is a performance monster that suffers from catastrophic engine failures due to a fundamental design flaw in the crankshaft and bearing assembly. When maintained meticulously and driven gently, they can be reliable, but most examples driven hard face expensive engine work before 100,000 miles.
M157 Engine Bearing and Crankshaft Failure
Common · high severityTypical onset: 60,000-90,000 mi
Symptoms: metallic knocking or ticking from lower engine, especially cold start, oil pressure warning light or low pressure readings, metal shavings in oil filter and oil pan, sudden catastrophic failure with loss of power
Fix: The M157 has undersized crankshaft journals and inadequate oiling to the main and rod bearings. Under hard use or even spirited driving, bearings wear prematurely and can spin, destroying the crankshaft. Requires complete engine teardown, crankshaft replacement, all bearings, and often pistons if debris circulated. 40-60 hours labor for short block replacement, more if heads need work. Some owners opt for full long-block replacement.
Estimated cost: $18,000-35,000
Transmission Oil Cooler Line Leaks
Common · medium severityTypical onset: 50,000-80,000 mi
Symptoms: transmission fluid puddle under vehicle, typically passenger side, burnt transmission fluid smell, transmission temperature warning, slipping or harsh shifts if fluid level drops significantly
Fix: The AMG Speedshift MCT transmission runs hot and the cooler lines at the radiator corrode or develop leaks at crimp points. Lines must be replaced as assemblies. Access requires removing undertray and sometimes front bumper components. 3-5 hours labor plus fluid refill and programming.
Estimated cost: $1,200-2,200
Transmission Mount Failure
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: clunk when shifting from Park to Drive or Reverse, excessive vibration at idle in Drive, visible transmission sag or movement when rocking vehicle, harsh engagement into gear
Fix: The hydraulic transmission mount degrades from heat and torque stress. Rubber separates from metal housing or fluid leaks out. Requires transmission support and removal of exhaust components for access. 2-3 hours labor. OEM mount is mandatory as aftermarket versions fail quickly.
Estimated cost: $800-1,400
Turbocharger Wastegate Rattle and Failure
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: rattling sound from engine bay on cold start that disappears when warm, loss of boost pressure and reduced power, check engine light with underboost codes P0234 or P003A, excessive black smoke under acceleration
Fix: Wastegate actuator arms wear at pivot points causing rattle, or actuators fail electrically. Can sometimes be resolved with actuator replacement only (8-12 hours per side), but often requires full turbo replacement due to shaft play or oil leakage. Turbos are integrated into exhaust manifolds, complicating replacement. Each side is 12-16 hours labor.
Estimated cost: $3,500-8,000
Air Suspension Strut Leaks
Occasional · medium severityTypical onset: 60,000-100,000 mi
Symptoms: vehicle sits low on one corner after sitting overnight, suspension warning light and Airmatic fault message, compressor runs excessively, hissing sound near wheel wells
Fix: Airmatic struts develop leaks at seal areas. Front struts are 2-3 hours each, rears are 2.5-3.5 hours each due to more complex mounting. Compressor often needs replacement simultaneously if it's been overworking. Programming required after replacement. Many owners convert to coilover suspension to eliminate future issues.
Estimated cost: $1,800-3,200 per strut, $2,500-4,000 for compressor
Rear Differential Bushing Failure
Occasional · low severityTypical onset: 50,000-90,000 mi
Symptoms: clunking from rear end on acceleration or deceleration, vibration through chassis at highway speeds, wandering or loose feeling in rear end during cornering, visible movement of differential housing when inspected on lift
Fix: The rear subframe bushings and differential mounts tear from the high torque loads. Requires subframe drop for proper replacement. Some bushings can be pressed individually but often multiple bushings need replacement simultaneously. 6-8 hours labor for comprehensive replacement, requires alignment afterward.
Estimated cost: $1,500-2,800
Only buy if you have a $20,000 emergency fund set aside for the inevitable M157 engine failure, or if you're prepared to drive it extremely gently and sell before 80,000 miles—not a car for enthusiast driving without accepting catastrophic financial risk.
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.