BMW's flagship performance coupé combines grand touring comfort with supercar acceleration. The S63 twin-turbo V8 is substantially improved over N63, but shares the hot-V design causing valve stem seal wear at high mileage. Main concerns: oil consumption (normal but monitor levels), coolant expansion tank failures (recall addressed many units), turbo actuator issues, rod bearing wear in early S63TU engines, and AC system problems on early 2020 models built before December 2019. Carbon ceramic brakes are expensive to replace (€16,000+ for full set). The xDrive system is generally reliable but transfer case shudder can occur - often resolved with fluid change.
Expected Annual Maintenance Costs
€2,750 - €5,400/year
15,000 km/year
Fixed costs
€1,800-€3,200
Risk buffer
€950-€2,200
What Can Break
bars = likelihood
Valve stem seal wear (high mileage)€4,000 - €7,000
Hot-V design accelerates seal degradation, causing oil consumption · more· less
The S63 shares the N63's "hot-V" design with turbos mounted in the valley between cylinder banks, creating extreme heat that degrades valve stem seals over time. Early S63 engines experienced failures around 60,000-80,000 km. The updated S63TU/TU2 versions have improved cooling with more coolant flow through the heads, pushing seal failure to 120,000-150,000 km. Symptoms include blue smoke on startup and gradual oil consumption increase. BMW considers up to 1 liter per 1,200 km "normal" for turbocharged engines, but consistent consumption above this indicates seal wear. Replacement requires cylinder head removal. All S63 engines will eventually need this repair at high mileage.
Coolant expansion tank failure€200 - €2,500
Plastic tank cracks from heat cycles, causing coolant loss · more· less
BMW expansion tanks are known weak points across all models. On the M8, tank failures have been documented as early as 20,000 km. The mechanism is stress cracking from repeated heat/cool cycles that makes plastic brittle. Warning signs: coolant level indicator stops moving, visible cracks, or coolant pooling under expansion tank. BMW issued a recall for this issue. One documented case: F92 owner had tank replaced twice under warranty, then experienced catastrophic engine failure at 28,000 km when coolant leaked into cylinders. If tank fails while driving and coolant enters combustion chambers, engine can seize. Simple tank replacement costs €200-400 parts and labor. Engine damage from coolant intrusion: €2,500-10,000+. Check tank condition at every service - look for dark discoloration on dipstick which indicates tank nearing end of life.
Twin turbos stressed by heat and performance use, oil starvation critical · more· less
The S63's twin turbos are mounted in the hot-V configuration and operate under extreme conditions. Most common failure: turbo oil feed/return line blockage from carbon buildup, causing oil starvation and bearing failure. BMW issued TSB B11 07 11 addressing this. Actuator failures occur when wastegate actuators stick due to carbon deposits - more common with gentle driving or short trips. Symptoms: EPC warning light, limp mode, loss of boost. Turbo replacement typically €2,000-2,500 per turbo including labor. Full system replacement if both fail: €4,000-5,000. Oil changes every 5,000-8,000 km (not BMW's 15,000 km interval) dramatically reduce failure risk. For track use, change oil every 6,000 km maximum. Quality synthetic oil (BMW LL-01 or LL-04 spec minimum) essential.
If optioned with CCB, rotors cost over €4,000 each to replace · more· less
Carbon ceramic brakes are an expensive option on the M8, and replacement costs are staggering. CCB rotors last 80,000-150,000 km under normal street driving, but track use significantly accelerates wear - especially if operating above pad temperature threshold. Each rotor costs over €4,000. Complete four-rotor replacement: €16,000-20,000. M8 is a heavy car (1,900+ kg) with immense power, generating extreme heat under hard braking. Many specialists recommend converting to iron rotors (€2,500-4,000 total) which perform identically on street and offer cheaper replacement (rotor rings €200-400 each). If buying used M8 with CCB, inspect rotors carefully for cracks, measuring thickness. Budget for eventual replacement unless converting to iron.
Rod bearing wear (early S63TU engines)€8,000 - €15,000
Rare but catastrophic - early engines more susceptible, track use accelerates · more· less
Rod bearing failure is BMW's most infamous issue, affecting S54/S65/S85 engines significantly. S63 less prone than those engines, but early S63TU versions (2019-2020 M8) had documented failures. One reported case: 2022 M8 Competition with 6,000 km experienced rod bearing failure and crankshaft break. When rod bearings wear, they score the crankshaft and eventually cause rod knock, piston slap, and complete engine destruction if not caught early. Primary causes: inadequate oil pressure during cold starts, extended oil change intervals, repeated high-RPM use without proper warm-up. BMW doesn't list rod bearings as maintenance items, but many specialists recommend inspection/replacement every 80,000-120,000 km for track-driven cars (60,000 km for heavy track use). Oil analysis can detect bearing wear early. Later S63TU2/TU4 engines (2021+) have improved bearing design and metallurgy. Complete engine rebuild if bearings fail: €8,000-15,000.
AC system failure (2020 models)€1,500 - €4,000
2020 M8s built before Dec 2019 have widespread AC problems · more· less
Early 2020 BMW M8 models (production before December 2019) experienced significant AC system failures. Common symptoms: blowing hot air when cooling requested, temperature fluctuating with engine RPM, intermittent cooling. Multiple owners reported complete AC system replacement required - condenser and compressor. Parts availability was problematic, with repair timelines exceeding 1 month. Condenser/compressor replacement cost: €1,500-2,500. Full system replacement if refrigerant lines also damaged: €3,000-4,000. Some cases resolved with refrigerant recharge (€80-250) or simple climate control setting adjustment - check Vehicle Climate Control menu for air mixture setting pushed to warm (red) side. BMW appears to have resolved this issue in later 2020 production and 2021+ models. If buying 2020 M8, verify production date and AC functionality during extended test drive (minimum 30 minutes with AC on maximum cold).
xDrive transfer case shudder / failure€300 - €10,000
Jerking during cornering or acceleration, often fixed with fluid change · more· less
BMW xDrive transfer cases developed shuddering/jerking issues affecting multiple models including F92 M8. BMW TSB 27-02-20 addresses this. Symptoms: jerking or shuddering during cornering, low-speed acceleration, or driving with light throttle. Often no warning lights appear. Common causes: factory-filled transfer case oil doesn't meet BMW specs after break-in period, or mismatched/unevenly worn tires keeping xDrive constantly engaged. Solution: transfer case oil change using proper BMW specification oil typically resolves issue (€250-400). Verify all four tires same brand/model and even wear - one worn tire can cause constant xDrive engagement and premature wear. If oil change doesn't resolve, transfer case may need replacement: €7,000-10,000. Note: BMW class action lawsuit regarding transfer case defects specifically excludes M models, suggesting M-car transfer cases use different/more robust components. Most M8 owners report no issues.
Spark plug / ignition coil failure€400 - €800
Regular maintenance items, but premature failure causes misfires · more· less
BMW recommends spark plug replacement every 60,000 km, ignition coils every 40,000-60,000 km (unofficial recommendation - not in service schedule). V8 engine requires 8 plugs and 8 coils. Symptoms of failure: rough idle, loss of power, engine shaking, check engine light with misfire codes. BMW dealer pricing: spark plugs €50-70 each (€400-560 total), coils €70-80 each (€560-640 total). Independent shops: €300-500 for plugs and coils together. DIY costs significantly less: NGK spark plugs €8-15 each, quality aftermarket coils (Delphi/Bosch) €20-35 each - total parts €224-400. Labor: 2-3 hours. Special tool required: 14mm 12-point thin-wall spark plug socket. For M8 driven hard or on track, inspect/replace plugs every 40,000-50,000 km. Carbon buildup from short trips or gentle driving can foul plugs prematurely.
Common S63 issue - gaskets degrade from heat cycles · more· less
Oil leaks are one of the most common S63 issues, reported across all generations. Most frequent leak points: valve cover gaskets (both sides), oil filter housing gasket, oil pan gasket. The hot-V configuration with turbos creates extreme heat that accelerates gasket degradation. Valve cover gasket leaks typically appear at 60,000-100,000 km. Symptoms: oil smell in cabin, visible oil on engine, oil drips on ground after parking. Valve cover gaskets: €600-1,200 per side (€1,200-2,400 for both). Oil filter housing: €300-600. Oil pan gasket: €800-1,500 (labor intensive - requires subframe drop). Small leaks aren't urgent but should be addressed within months - oil contacting hot exhaust creates fire risk. Check oil level every 1,000 km regardless of consumption warning - S63 uses 8.4-9.5 liters, and running low damages turbos and bearings. About 8% of BMW warranty claims for S63 relate to oil leaks.
Powerful and capable, but expect high running costs
The M8 Competition is BMW's most powerful production car, and the S63TU engine is substantially more reliable than the notorious N63. However, it shares the hot-V design that causes inevitable valve stem seal wear at high mileage and accelerates gasket degradation. Early 2020 models have documented AC and rod bearing issues. Budget €3,000-4,000 annually for maintenance if driven normally, more if tracked. Oil consumption is normal - monitor levels every 1,000 km. The platform is fundamentally sound and capable of 250,000+ km with diligent maintenance, but repairs are expensive when they occur.
Pre-Purchase Inspection Checklist
General checks
Complete service history
BMW dealer or authorized M specialist records essential. Verify oil changes every 10,000 km maximum (5,000-8,000 km ideal for M cars).
Cold start inspection
Engine must be completely cold (overnight). Listen for rattles, watch for blue smoke from exhaust indicating valve stem seal wear.
Oil consumption check
Ask owner about oil consumption. Up to 1L per 1,200 km is within BMW spec but high consumption suggests valve stem seals wearing.
Extended test drive
Minimum 30-45 minutes including highway speeds, hard acceleration, and varied conditions to heat engine/transmission fully.
Tire inspection
All four tires must be same brand/model with even wear. Mismatched tires cause xDrive problems. M8 rear tires wear faster - budget €1,000-1,500/year for tires with spirited driving.
Specific for this vehicle
Check coolant expansion tank condition
Inspect tank for cracks, discoloration. If level indicator doesn't move, tank may be failing. This is critical - tank failure can destroy engine if coolant enters cylinders.
Verify 2020 production date if applicable
2020 M8s built before December 2019 have widespread AC problems. Test AC thoroughly - 30+ minutes at maximum cold on hot day.
Oil leak inspection
Check valve covers, oil filter housing, oil pan for leaks or seepage. Look for oil accumulation in engine bay. Small leaks worsen quickly.
xDrive transfer case test
During test drive, feel for jerking or shuddering during slow-speed turns and gentle acceleration. Often indicates transfer case needs fluid change.
Carbon ceramic brake inspection (if equipped)
Measure rotor thickness, inspect for cracks or damage. Replacement costs €16,000+. Consider negotiating significant discount if rotors worn or converting to iron brakes.
Scan for stored fault codes
Professional BMW scan tool required. Check for history of misfire, turbo, cooling system, or transmission codes even if cleared.
Verify all recalls completed
Coolant expansion tank recall, seatbelt buckle sensor recall (2020). Use VIN to verify with BMW dealer.
Rod bearing condition (if high mileage)
Oil analysis recommended for cars over 60,000 km. Can detect rod bearing wear before catastrophic failure. Blackstone Labs or similar service.
Check service history for track use
Track use dramatically accelerates wear on brakes, tires, transmission, differential. If tracked, verify shortened service intervals were followed.
Recalls and Technical Service Bulletins
Coolant expansion tank failure (2019-2021)Verify completed
Front seat belt buckle sensor (2020 F92)Recall 20V-164
Backup camera display malfunction (various years)Check with dealer
Turbocharger oil supply/return line blockage (TSB)B11 07 11
xDrive transfer case shudder (TSB)27-02-20
Hydraulic brake unit weld failure (2019-2020)Check with dealer
Contact BMW dealer with VIN to verify all recalls completed. The coolant expansion tank recall is particularly important - failure can cause catastrophic engine damage.
Warranty Status
Factory warranty (4 years / 50,000 miles)Expired on 2019-2021 models
BMW complimentary maintenance3 years / 36,000 miles from new
Extended warranty (Platinum)€5,000-€8,000 for 3 years
Rust perforation warranty12 years / unlimited miles
2019-2021 M8 models are outside factory warranty. Extended warranty available through BMW dealers at €5,000-8,000 for 3-year Platinum coverage, but may be worth it given repair costs (valve stem seals €4,000-7,000, turbos €2,000-5,000, engine rebuild €8,000-15,000). Note: extended warranties typically exclude normal wear items and may not cover failures from track use. Read policy carefully.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.