The 2021 GLE350 W167 with the M264 2.0L turbo four-cylinder is plagued by catastrophic engine failures due to crankshaft bearing defects and inadequate oiling under certain conditions. This is Mercedes' most problematic modern powertrain, with failures occurring at shockingly low mileages and requiring complete engine rebuilds or replacements.
M264 Crankshaft Bearing Failure / Spun Bearings
Common · high severityTypical onset: 20,000-60,000 mi
Symptoms: Sudden knocking or rattling noise from bottom end at idle or under load, Metal shavings in oil or oil filter during service, Low oil pressure warning light, Complete engine seizure in worst cases
Fix: Full engine teardown required. Main and rod bearings fail due to manufacturing defects in crankshaft journals and inadequate oil delivery. Most shops recommend short block replacement rather than rebuild due to crankshaft damage. 18-25 labor hours for short block swap.
Estimated cost: $15,000-22,000
M264 Piston Ring Failure / Carbon Buildup
Common · high severityTypical onset: 30,000-70,000 mi
Symptoms: Excessive oil consumption (1 quart per 1,000 miles or worse), Blue smoke from exhaust on startup or acceleration, Misfires and rough idle, Check engine light with lean codes or misfire codes
Fix: Piston rings seize in lands due to carbon deposits and weak ring tension from factory. Requires cylinder head removal, honing, new pistons and rings. Often combined with bearing replacement if caught early. 20-28 labor hours.
Estimated cost: $8,000-14,000
9G-Tronic Transmission Oil Cooler Leaks
Occasional · medium severityTypical onset: 40,000-80,000 mi
Symptoms: Transmission fluid puddles under vehicle near front, Low transmission fluid warnings, Harsh or delayed shifting when fluid level drops, Pink or red fluid visible on oil cooler lines
Fix: Oil cooler develops leaks at crimped line connections or through internal corrosion. Requires cooler replacement and transmission fluid flush. 4-6 labor hours including proper fluid fill procedure.
Estimated cost: $1,200-2,000
Transmission Mount Failure
Occasional · low severityTypical onset: 50,000-90,000 mi
Symptoms: Clunk or thud when shifting from Park to Drive or Reverse, Vibration through floorboard at idle in gear, Excessive driveline movement visible during throttle application
Fix: Rubber transmission mount separates or collapses. Common on all W167 models due to weight of engine-transmission assembly and thin mount design. 2-3 labor hours, requires supporting powertrain.
Estimated cost: $600-900
High-Pressure Fuel Pump Failure
Occasional · medium severityTypical onset: 35,000-65,000 mi
Symptoms: Extended cranking before starting, especially when hot, Loss of power under acceleration, Check engine light with fuel pressure codes (P0087, P228C), Rough idle or stalling
Fix: M264 high-pressure fuel pump (mounted on cylinder head) fails internally, cannot maintain 2,900+ psi rail pressure. Fuel filter replacement rarely helps. Pump and seal replacement required. 3-4 labor hours.
Estimated cost: $1,800-2,800
Airmatic Air Suspension Compressor Failure
Occasional · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Vehicle sits low, especially at one corner, Compressor runs constantly or excessively, Suspension warning messages on dash, Hissing noise from rear of vehicle
Fix: Air suspension compressor overworks and burns out, often due to leaking air springs or lines. Must diagnose leaks first before compressor replacement. Compressor replacement 2-3 hours, but finding leaks adds time.
Estimated cost: $2,200-3,500
Absolutely would not buy one used without factory warranty remaining or a comprehensive third-party warranty covering engine internals — the M264 engine failure rate is unacceptable and repairs often total the vehicle.
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.