Iconic performance coupe for enthusiasts who prioritize driving dynamics. The S55 twin-turbo engine is generally robust with proper maintenance, but the notorious crank hub issue looms over both stock and tuned examples. Oil leaks (valve cover gasket especially) are common after 60,000 km, turbo wastegate rattle develops on higher mileage cars, and DCT-equipped models can experience jerky shifts or mechatronic failures. Manual transmission variants are more reliable. Carbon buildup requires walnut blasting around 100,000 km. Parts are expensive and labor costs are high due to complexity. Budget significantly more for tracked or modified cars.
Press-fit hub can slip under load, throwing off timing and potentially causing catastrophic engine damage · more· less
The S55's factory crank hub uses a press-fit design (no keyway or pin). Under high loads or prolonged vibrations, the crank bolt can loosen, allowing the hub to slip. This happens abruptly with no warning signs. Estimated to affect less than 10% of S55 engines throughout their lifetime, but risk increases significantly on tuned cars (Stage 2+). BMW issued an extended warranty for 2014-2015 cars through 50,000 miles. Preventive fix: crank bolt capture plate (€400-700 parts + labor, no engine removal needed). Full crank hub replacement if already spun: €1,500-2,500. If timing jumped and caused piston-to-valve contact, complete engine rebuild can exceed €10,000.
Valve cover gasket oil leak€1,200 - €2,000
Rubber gasket cracks from heat stress, oil drips onto hot exhaust causing smoke · more· less
One of the most common M4 issues. High temperatures cause the rubber valve cover gasket to crack and leak, often before 60,000 km. Oil drips directly onto exhaust pipes below, creating noticeable smoke and burning oil smell. The S55's plastic valve covers can also crack (less common than gasket failure). Replacement typically costs €1,200-1,500 at independent BMW specialists, €1,800-2,000 at dealers. Oil pan gasket and oil filter housing gasket leaks are also common, with oil pan replacement often exceeding €2,000 due to labor.
Wastegate actuator wears, causing rattle and reduced performance; turbo seals can also fail · more· less
The wastegate valve doesn't completely close due to mechanical tolerances, resulting in repeated clanking against its seat. Wastegate actuator alone costs €650 (genuine BMW electronic actuator for S55). Labor to remove/reinstall turbos adds significantly. Full turbo replacement (if seals fail or internals damaged) runs €2,000-4,000 for both turbos including labor. High oil consumption (1L per 500 miles or worse) often indicates turbo seal failure - white smoke from exhaust when lifting off throttle after hard driving is a telltale symptom.
Dual-clutch transmission shows jerky shifts, delays into reverse, clutch overheating on track · more· less
The 7-speed DCT is fast but problematic. Common complaints include jerky shifts (especially when cold), delay engaging reverse after sitting, and clutch overheating under aggressive driving. Early cars had software issues causing jerkiness. Mechatronic unit repairs typically cost €2,000-4,000. Complete transmission rebuild runs €3,500-7,000. DCT fluid becomes metallic-tinted by 60,000 km - change every 50,000 km to minimize wear. Manual transmission models are significantly more reliable, though clutch replacement at 80,000-100,000 km costs €2,000-2,500.
Carbon buildup on intake valves€800 - €1,200
Direct injection causes carbon deposits; requires walnut blasting around 100,000 km · more· less
Direct fuel injection means fuel doesn't wash intake valves clean. Carbon accumulates over time, reducing airflow and causing rough idle, sluggish throttle response, and reduced power. Walnut blasting (compressed air blasts crushed walnut shells to remove carbon) is the standard fix. Requires removing intercooler to access valves. Dealer cost typically €1,000+, independent specialists €800-1,000. An oil catch can (€200-400 installed) helps prevent future buildup by intercepting oil vapor before it reaches intake manifold.
Rear differential bushing failure€600 - €1,400
Rubber bushings wear from hard launches, causing clunking under acceleration · more· less
Aggressive launches and hard driving wear rear differential bushings. Symptoms include clunking from rear end under acceleration or gear changes, and excessive drivetrain slack. Independent shops charge around €600-800, BMW dealers approximately €1,100-1,400. Labor represents 90% of cost (6-9 hours) due to subframe removal. Important: rear subframe bolts are one-time-use only and must be replaced - reusing old bolts may damage body threads. Many owners upgrade to polyurethane bushings (€100-150 parts) during replacement for increased durability.
Water pump/thermostat failure€700 - €1,400
Electric water pump integrated with thermostat housing fails around 100,000 km · more· less
The S55 uses an electric water pump integrated with the thermostat housing. Failures common around 100,000 km. Symptoms include coolant warning light, engine overheating, or poor cabin heating. OEM pump/thermostat kit costs approximately €500. Labor adds another €500-700 at independent shops, €700-900 at dealers. BMW recommends replacement every 60,000 miles (96,000 km) for preventive maintenance. Pierburg is the OEM manufacturer - aftermarket OEM-equivalent parts from quality suppliers save money while maintaining reliability.
Electronic dampers fail or stick at full stiff when acceleration sensor degrades · more· less
Cars with Adaptive M Suspension use EDC (electronic damper control). When the acceleration sensor fails due to age, the system has no reference and defaults to fully stiff ride. Genuine BMW adaptive/EDC struts cost approximately €1,000 each. Replacing all four corners with OEM parts costs over €4,000 plus labor. Many owners facing failure switch to aftermarket coilovers (KW V3 with EDC cancellation €3,500-4,500 installed, KW DDC adaptive system €5,500-6,500). Standard non-adaptive suspension M4s avoid this issue entirely.
Two separate recalls for slip-joint and flange failures; free dealer fix · more· less
First recall (2015-2016): 42 cars had slip-joint without grease from factory, can fail causing loss of rear wheel drive. Second recall (2016-2017): 2,661 cars had driveshaft flange with insufficient durability - connection can loosen and separate completely. Symptoms include noise, vibration, loss of power. BMW replaces driveshaft free of charge. Contact BMW with VIN to verify both recalls completed before purchase.
Intercooler/charge air cooler leak€800 - €2,500
OEM intercooler can leak coolant into combustion chambers causing catastrophic damage · more· less
Known faulty equipment on S55 engine. Internal intercooler leak allows coolant into combustion chambers, potentially causing severe engine damage. Symptoms: coolant loss (check expansion tank regularly), error code 20A201 (aux pump coolant loss), white smoke from exhaust (coolant burning), hesitation under load. Check J-pipe and throttle body for coolant residue. Normal to lose 100-200ml coolant per 5,000 km. Replacing intercooler and upgrading charge pipes/J-pipes to aluminum (plastic OEM pipes prone to failure) costs €800-1,500 parts, €1,000-2,500 total with labor. Expansion tank seals also crack commonly (simple €100-200 fix).
High performance comes with high maintenance costs
The M4 F82 is a capable performance machine that can be reliable with diligent maintenance, but it's not a cheap car to own. The S55 engine is generally robust when serviced properly (oil changes every 5,000-8,000 km recommended), but several expensive issues are common enough to warrant budgeting. Crank hub failure remains a concern even on stock cars. Manual transmission examples are more reliable than DCT. Cars with full BMW dealer service history and documented preventive maintenance (crank hub capture plate, regular oil changes, carbon cleaning) command premium pricing for good reason. Expect to spend significantly more than a standard 4-Series.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete BMW dealer or specialist records essential. Verify oil changes at 5,000-10,000 km intervals, not just following CBS system.
Cold start
Must start engine completely cold. Listen for excessive ticking (cam timing issue) or unusual noises in first 30 seconds.
Body condition
Check for accident damage, paint mismatch. Side bolsters on front seats wear quickly - inspect for smoothing and creased leather.
Test drive
Minimum 30 minutes including highway speeds. DCT needs to reach operating temperature to reveal issues.
Specific for this vehicle
Check for valve cover oil leaks
Inspect around valve cover perimeter and underneath car. Burning oil smell or smoke from engine bay indicates leak onto exhaust.
Listen for turbo wastegate rattle
At idle, listen for metallic rattling from engine bay. Drive hard then lift off throttle - white smoke indicates turbo seal failure.
Verify crank hub status/preventive work
Ask seller if crank hub capture plate or upgraded hub has been installed. 2014-2015 cars: check if extended warranty claim was filed.
Test DCT operation thoroughly (if equipped)
Drive for 20+ minutes until transmission is hot. Check for jerky shifts, delay engaging reverse after parking, clunking. Pull transmission dipstick if accessible - metallic sheen in fluid indicates wear.
Check oil level and consumption history
Verify oil level is correct. Ask owner about consumption rate - anything over 1L per 2,000 km warrants investigation. Check for oil residue in intake/intercooler piping.
Verify driveshaft recalls completed
2015-2016 cars (slip-joint recall) and 2016-2017 cars (flange recall). Contact BMW with VIN before purchase.
Check for rear differential clunking
Drive aggressively and listen for clunks from rear during acceleration or gear changes. Indicates worn differential bushings.
Inspect coolant level and condition
Check expansion tank - should be between min/max when cold. Brown/milky appearance indicates contamination. Loss exceeding 200ml per 5,000 km may indicate intercooler leak.
Test adaptive suspension (if equipped)
Cycle through Comfort/Sport/Sport+ modes. All should feel distinctly different. If stuck on harsh ride, EDC has likely failed.
Check for interior rattles and sticky buttons
Test all buttons and switches. Dashboard rattles over bumps are common but annoying. Soft-touch coating degradation is age-related.
Crank hub extended warranty (2014-2015, up to 50k miles)Now expired
Takata airbag inflator (various production dates)Verify completed
DCT software updates for jerky shifting (early cars)Check with dealer
Contact BMW with the VIN to verify all recalls completed. The two driveshaft recalls are critical safety issues. Early DCT software updates may improve shift quality if not already applied.
Warranty Status
Factory warranty (4 years/80,000 km)Expired on all F82s
BMW extended warranty (Platinum)€1,400-2,000/year
Third-party extended warranty€1,000-1,500/year
All F82 M4s (2014-2020) are now outside original factory warranty. Extended warranty options available from BMW (Platinum/Gold tiers) or third-party providers. Be aware that extended warranties often have exclusions (oil leaks, wear items) and may require dealer diagnostics before approval. Thoroughly review coverage details and exclusions before purchasing. Some owners report difficulty getting claims approved through warranty insurers.
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.