The 2024 McLaren 720S with its M840T 4.0L twin-turbo V8 is a technological marvel, but the platform shows critical weaknesses in the transmission cooling system and catastrophic engine failures tied to connecting rod bearing issues—problems that can financially total the car.
Catastrophic Engine Bearing Failure (Rod/Main Bearings)
Occasional · high severityTypical onset: 15,000-40,000 mi
Symptoms: Sudden metallic knocking from engine bay especially under load, Oil pressure warning light, Metal debris in oil filter during service, Engine seizure in worst cases
Fix: Complete engine rebuild or short block replacement required. 40-60 hours labor for short block R&R with ancillaries, more for full rebuild with head work. This is the death sentence issue on this platform—bearings fail prematurely even with proper maintenance.
Estimated cost: $45,000-85,000
Transmission Oil Cooler Failure
Common · high severityTypical onset: 20,000-50,000 mi
Symptoms: Transmission overheating warnings on dash, Harsh shifting or failure to engage gears, Burning smell from transmission tunnel, Limp mode activation
Fix: Replace transmission oil cooler and flush entire system. 8-12 hours labor due to carbon tub access limitations. Often requires transmission removal for proper inspection. This is THE common failure point.
Estimated cost: $6,500-12,000
Dual-Clutch Transmission Mount Failure
Common · medium severityTypical onset: 25,000-60,000 mi
Symptoms: Clunking noise during launches or hard shifts, Excessive drivetrain vibration, Transmission feels like it moves during acceleration, Misalignment causing clutch wear
Fix: Replace transmission mounts. Requires dropping rear subframe for access. 6-10 hours labor. Often discovered during other transmission work.
Estimated cost: $3,500-6,000
Head Gasket Failure (Related to Bearing Issues)
Occasional · high severityTypical onset: 30,000-70,000 mi
Symptoms: White smoke from exhaust, Coolant loss with no visible leaks, Overheating episodes, Oil contamination with coolant (milky on dipstick)
Fix: Head gasket replacement on both banks. 35-45 hours labor given carbon fiber body work removal and engine bay complexity. Often discovered alongside bearing wear, so check bearings thoroughly during any head work.
Estimated cost: $25,000-40,000
Fuel Filter Clogging (Carbon Buildup)
Occasional · medium severityTypical onset: 40,000-80,000 mi
Symptoms: Intermittent power loss under full throttle, Engine stumbling or misfires at high RPM, Fuel pressure fault codes, Reduced performance in hot weather
Fix: Replace fuel filter and inspect fuel pumps. 3-5 hours labor with tank access complications. McLaren recommends service interval ignored by many owners.
Estimated cost: $1,200-2,500
Shift Solenoid Pack Failure
Occasional · medium severityTypical onset: 35,000-65,000 mi
Symptoms: Delayed or harsh gear changes, Transmission stuck in one gear, Check engine light with transmission codes, Erratic shifting patterns
Fix: Replace all shift solenoids as a set. 10-14 hours labor with transmission partial disassembly. Do NOT replace individually—they fail in clusters.
Estimated cost: $7,000-11,000
Avoid unless under full warranty or you have $50K+ set aside for catastrophic engine failure—the bearing issue is a platform-wide ticking time bomb that makes this a financial landmine in the used market.
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.