The 2016 M760i with the N74B66 6.6L twin-turbo V12 is BMW's flagship luxury sedan that suffers from catastrophic engine failures due to design flaws in the crankshaft bearing journals and inadequate oiling under specific conditions. When these engines fail, they fail spectacularly and expensively, often requiring complete engine rebuilds or replacement.
Catastrophic Crankshaft and Rod Bearing Failure
Common · high severityTypical onset: 40,000-80,000 mi
Symptoms: Metallic knocking or rattling from engine at idle that worsens with RPM, Metal shavings visible in oil during changes, Low oil pressure warnings despite proper oil level, Sudden catastrophic failure with complete engine seizure in severe cases
Fix: Complete engine-out rebuild required. Replace crankshaft, all rod bearings, main bearings, inspect/replace pistons and rings. Minimum 60-80 labor hours for engine removal, disassembly, machine work, reassembly, and reinstallation. Many shops recommend short block replacement instead due to liability concerns.
Estimated cost: $25,000-45,000
Piston Ring Land Failure and Bore Scoring
Occasional · high severityTypical onset: 50,000-90,000 mi
Symptoms: Excessive oil consumption (1 quart per 500-1000 miles), Blue smoke from exhaust on startup or acceleration, Misfires and rough idle, especially when cold, Loss of compression in affected cylinders
Fix: Engine removal required. Inspect cylinder bores for scoring—if scored, needs bore/hone or block replacement. Replace all pistons, rings, hone cylinders if viable. Often discovered during bearing failure diagnosis. 70-90 hours total with block work.
Estimated cost: $28,000-50,000
Transmission Oil Cooler Line Leaks
Common · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Transmission fluid puddles under vehicle, usually passenger side, Burnt transmission fluid smell, Transmission overheating warnings on display, Harsh shifts or slipping if fluid level drops significantly
Fix: Replace transmission oil cooler lines and seals. Access requires removal of undertray and sometimes suspension components. 4-6 hours labor. Address immediately to prevent transmission damage from overheating.
Estimated cost: $800-1,500
Transmission Mount Failures
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Clunking when shifting from Park to Drive or Reverse, Excessive drivetrain vibration at idle in gear, Visible transmission sag or movement when rocking vehicle, Harsh engagement during shifts
Fix: Replace transmission mounts—engine-out not required but access is tight. Typically replace both side mounts and crossmember mount. 3-5 hours depending on access and special tools needed. The V12 makes this job harder than on six-cylinder models.
Estimated cost: $1,200-2,200
Turbocharger Wastegate Rattle and Failure
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Rattling noise from engine bay on cold start that disappears when warm, Reduced boost pressure and sluggish acceleration, Check engine light with underboost codes (P0299, P0234), Excessive black smoke under hard acceleration
Fix: Replace affected turbocharger(s). Twin-turbo V12 has two turbos. Labor is 8-12 hours per side due to tight packaging. Often one fails first, but both should be inspected. Includes new gaskets, oil feed lines, coolant lines.
Estimated cost: $4,500-8,000 per turbo
Fuel Injector Carbon Buildup and Failure
Occasional · low severityTypical onset: 70,000-100,000 mi
Symptoms: Rough idle and misfires, especially on cold starts, Reduced fuel economy, Hesitation during acceleration, Check engine light with misfire codes on specific cylinders
Fix: Direct injection engines prone to carbon buildup. Walnut blasting intake valves recommended every 50-60k miles (12-15 hours). If injectors failed, replacement is 6-8 hours for all twelve injectors. V12 makes access difficult on rear cylinders.
Estimated cost: $3,500-6,000 for injector replacement, $1,500-2,500 for walnut blasting service
Absolutely not—the N74 V12 has a documented pattern of catastrophic engine failures that make this a financial nightmare unless you have a comprehensive warranty and deep pockets for a $40k+ engine rebuild.
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.