The 2019 S450 W222 with M276 3.0L BiTurbo is late enough to dodge some earlier balance shaft issues, but the engine's fundamental design vulnerabilities still surface—particularly oil consumption and bearing wear that can escalate to catastrophic failure if ignored.
Excessive Oil Consumption Leading to Bearing Failure
Occasional · high severityTypical onset: 60,000-100,000 mi
Symptoms: Low oil warning between service intervals, Blue smoke on cold start, Metallic rattling from engine at idle, Check engine light for bank-specific misfire
Fix: Piston ring wear or valve stem seals allow oil burning; if caught early, top-end refresh (seals, rings) runs 18-24 hours. If bearings are scored from oil starvation, you're into connecting rod bearings or full short block at 30-40 hours labor.
Estimated cost: $4,500-9,000 for rings/seals; $12,000-18,000 for short block
Transmission Oil Cooler Leak
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: ATF spots under vehicle, Transmission overheat warning, Sluggish shifts when hot, Pink residue near radiator support
Fix: 9G-TRONIC cooler lines and internal cooler seals fail; replacement requires front bumper removal and radiator support access. 4-6 hours labor plus flush.
Estimated cost: $1,200-2,200
Transmission Mount Failure
Common · low severityTypical onset: 50,000-90,000 mi
Symptoms: Clunk on throttle tip-in or coast down, Vibration at idle in Drive, Visible separation or tearing of rubber isolator
Fix: Hydraulic mount degrades; requires lift access and subframe support. 2-3 hours labor, straightforward job.
Estimated cost: $600-1,100
High-Pressure Fuel Pump and Filter Clogging
Occasional · medium severitySymptoms: Long crank before start, Hesitation or stumble under load, Fuel pressure fault codes (P0087, P0191), Rough idle with VSC/traction light
Fix: Direct-injection pump or filter housing can clog from contamination or fail mechanically; filter is embedded in pump module. Replacement is 3-4 hours with proper fuel system depressurization.
Estimated cost: $1,400-2,400
Crankshaft Position Sensor Intermittent Failure
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: Random no-start, crank but won't fire, Stalling while driving with immediate restart, P0335/P0336 codes stored, Tachometer drops to zero then recovers
Fix: Sensor or reluctor ring contamination/wear; sensor itself is 1-2 hours, but if reluctor is damaged (rare), you're pulling the front cover. Almost always just the sensor.
Estimated cost: $350-700 for sensor; $2,500+ if reluctor involved
Turbocharger Wastegate Rattle and Boost Control Issues
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Rattle or buzz at 1,500-2,500 RPM under light load, Limp mode with underboost codes, Reduced power, especially on highway merges, Whistling or hissing under acceleration
Fix: Wastegate actuator arms wear or stick; turbos may need replacement if shaft play evident. Each turbo is 8-10 hours due to tight packaging and coolant/oil line work. Often both done together.
Estimated cost: $3,500-6,000 per side, $6,000-10,000 both
Buy a 2019+ with full service records and low oil consumption verified—skip high-mileage or neglected examples unless you have $5k contingency for engine internals.
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.