The 2023 E350 with the M264 2.0L turbo is relatively new but inherits known weaknesses from this engine family, particularly catastrophic internal engine failures tied to cylinder scoring and oil dilution. When these engines fail, they fail expensively and often suddenly.
M264 Cylinder Scoring / Catastrophic Engine Failure
Occasional · high severityTypical onset: 30,000-70,000 mi
Symptoms: excessive oil consumption (1qt per 1000 mi or more), metallic rattling or knocking at cold start, white/blue smoke from exhaust, sudden loss of compression, check engine light with misfire codes
Fix: Complete engine rebuild or short block replacement required. This is the big one—cylinder walls score due to inadequate oil film, aluminum debris circulates, destroys bearings. 20-30 labor hours for engine R&R plus rebuild time. Some MB goodwill cases exist but spotty coverage outside warranty.
Estimated cost: $12,000-20,000
Transmission Oil Cooler Leaks
Common · medium severityTypical onset: 40,000-80,000 mi
Symptoms: transmission fluid pooling under vehicle, low trans fluid warning, harsh shifting or slipping when fluid level drops, pink/red fluid visible near radiator area
Fix: 9G-Tronic trans cooler seals fail or cooler itself cracks. Requires cooler replacement, lines, flush. 3-5 hours labor depending on access. Catch it early before trans runs low and damages clutches.
Estimated cost: $800-1,500
Transmission Mount Failure
Common · low severityTypical onset: 50,000-90,000 mi
Symptoms: clunk or thud on acceleration or deceleration, excessive driveline vibration, visible sagging or torn rubber on mount
Fix: Rubber mounts deteriorate, especially on higher-torque tuned variants. Replacement is straightforward but requires lift and support of transmission. 2-3 hours labor.
Estimated cost: $400-700
Fuel Filter Clogging (Particulate Buildup)
Occasional · medium severitySymptoms: intermittent rough idle, hesitation under load, limp mode or reduced power warnings, hard starting after sitting
Fix: M264 high-pressure fuel system sensitive to contamination. Filter integrated with fuel pump module in tank on some variants. 2-3 hours labor to drop tank and replace pump/filter assembly. Use top-tier fuel to minimize.
Estimated cost: $600-1,200
Crankshaft and Bearing Failures (Secondary to Scoring)
Rare · high severityTypical onset: 40,000-80,000 mi
Symptoms: deep knocking noise from lower engine, metallic debris in oil, sudden oil pressure loss, engine seizure
Fix: When cylinder scoring goes undetected, aluminum and metal debris circulate and score main/rod bearings. Requires full crankshaft R&R, bearing replacement, block honing or replacement. Often discovered during teardown for other failures. 25-35 hours total.
Estimated cost: $10,000-18,000
Head Gasket Failures (Both Banks, Rare But Documented)
Rare · high severityTypical onset: 60,000-100,000 mi
Symptoms: coolant loss with no visible leaks, white smoke from exhaust, overheating, milky oil on dipstick, rough idle and misfire
Fix: Not common on M264 but documented in severe overheat or detonation cases. Head removal, resurface, gasket set, timing components, fluids. 14-18 hours labor.
Estimated cost: $4,500-7,000
Skip it unless CPO with transferable warranty—M264 engine is a ticking time bomb with catastrophic repair costs that exceed the depreciated value of the car.
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.