The 2020 Ghost shares the N74 6.6L twin-turbo V12 with BMW's 7-Series, and while it's a magnificent engine when healthy, it has notorious weak points—particularly carbon buildup, cooling system failures, and catastrophic bearing failures that can grenade the entire bottom end.
N74 V12 Connecting Rod and Main Bearing Failure
Occasional · high severityTypical onset: 60,000-100,000 mi
Symptoms: Metallic knocking from engine bay especially on cold starts, Low oil pressure warnings, Metal shavings in oil during changes, Sudden catastrophic failure with no warning in worst cases
Fix: This is the big one—rod bearings wear prematurely due to marginal oiling and tight tolerances. Requires full engine-out rebuild with upgraded bearings, new hardware, and machining if journals are scored. Plan 60-80 labor hours for complete rebuild including removal/installation. Many shops won't touch it; you're looking at specialist territory.
Estimated cost: $25,000-45,000
Severe Carbon Buildup on Intake Valves
Common · medium severityTypical onset: 40,000-70,000 mi
Symptoms: Rough idle and misfires, Loss of power especially under boost, Hesitation on acceleration, Check engine light with multiple misfire codes
Fix: Direct injection means no fuel wash on valves. Requires walnut blasting both cylinder banks—12-16 hours labor because of tight engine bay packaging and intake manifold complexity. Preventive cleaning every 40k miles recommended.
Estimated cost: $2,800-4,500
ZF 8-Speed Transmission Oil Cooler and Solenoid Failures
Occasional · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Harsh or delayed shifts, Transmission going into limp mode, Fluid leaks from cooler lines, Intermittent shift quality issues
Fix: The ZF8HP can develop internal solenoid failures or external cooler leaks. Solenoid replacement requires valve body removal (8-12 hours), full fluid flush, and adaptation. Cooler replacement adds 4-6 hours. This transmission is sealed-for-life but absolutely needs fluid changes every 40k miles despite what RR says.
Estimated cost: $3,500-6,500
Turbocharger Wastegate Rattle and Boost Control Issues
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Rattling noise on cold start that disappears when warm, Overboosting or underboost codes, Reduced power and limp mode, Turbo whistle or unusual spool sounds
Fix: Wastegate actuator arms wear and rattle, or electronic actuators fail. Each turbo requires removal from underneath—extremely tight access. Plan 14-18 hours per side for replacement. If you catch it early, sometimes actuators can be replaced without full turbo swap.
Estimated cost: $4,500-8,000
Coolant System Failures (Water Pump, Hoses, Expansion Tank)
Common · high severityTypical onset: 50,000-80,000 mi
Symptoms: Coolant warning lights, Overheating especially in traffic, Visible leaks under vehicle, Sweet smell from vents, Steam from engine bay
Fix: The V12 cooling system is complex with electric water pumps, multiple thermostats, and brittle plastic components. Water pump failure is common—8-12 hours labor due to access. Recommend replacing expansion tank, all hoses, and thermostats as preventive maintenance when doing pump. Overheating this engine even once can warp heads.
Estimated cost: $2,500-5,000
Air Suspension Compressor and Strut Failures
Occasional · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Vehicle sitting low on one or more corners, Suspension warning lights, Compressor running constantly, Harsh ride quality, Inability to raise vehicle
Fix: Air struts leak at seals, compressor wears out from overwork. Each strut is 3-4 hours, compressor is 4-6 hours. Parts are eye-wateringly expensive and must be OEM or genuine BMW equivalents—no aftermarket worth using. Budget for all four struts if one fails above 80k miles.
Estimated cost: $3,000-7,000
Only buy if you have $5,000-10,000 per year budgeted for maintenance and can accept that a catastrophic engine failure could total the car financially—find one with full service records showing preventive bearing service or walk away.
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.