The last rear-wheel-drive hot hatch from BMW, beloved by enthusiasts. The B58 engine is widely praised as one of BMW's most reliable modern powerplants - significantly better than the older N54 and N55. Major concerns include valve cover gasket leaks (60,000-100,000 km), carbon buildup requiring walnut blasting every 50,000-70,000 km, water pump failures (70,000-100,000 km), and early B58 fuel injector failures (pre-Aug 2017). Oil filter housing gaskets can fail and cause coolant leaks. ZF 8-speed automatic is generally reliable but sensitive to fluid level and quality. Buy on condition not mileage - many have been driven hard. Verify crankshaft sensor recall completed (May-July 2018 production).
Expected Annual Maintenance Costs
€1,100 - €2,100/year
15,000 km/year
Fixed costs
€700-1,100
Risk buffer
€400-1,000
What Can Break
bars = likelihood
Valve cover gasket oil leak€500 - €1,200
Rubber gasket degrades from heat cycles, begins leaking around 60,000-100,000 km · more· less
The B58's valve cover gasket is prone to failure as the rubber material ages and goes through many heat cycles. Oil leaks onto the ignition coils and down the side of the engine. The gasket itself is inexpensive (€40-100), but dealer labor runs €450-1,100 because parts of the firewall must be removed to access the valve cover. Independent specialists charge €500-800 total. This is a common BMW issue across most engines. Replacement typically needed every 80,000 km on the B58 (better than the N55 which needs it at 60,000 km).
Carbon buildup on intake valves€300 - €750
Direct injection causes carbon deposits, requires walnut blasting every 50,000-70,000 km · more· less
As a direct injection engine, the B58 is prone to carbon buildup on intake valves because fuel doesn't wash over them. Symptoms include rough idle, loss of power, reduced fuel efficiency, and engine misfires. Walnut blasting (professional media blasting service) costs €300-400 at independent specialists, or €600-750 at BMW dealers including new intake manifold gaskets. This is preventive maintenance, not a defect - all direct injection engines need this. Using premium fuel and occasional spirited driving helps reduce buildup rate. Recommended every 50,000-70,000 km.
Water pump failure€600 - €1,200
Electric water pump integrated with thermostat typically fails 70,000-100,000 km · more· less
The B58 uses an electric water pump integrated with the thermostat housing. Failures are common between 70,000-100,000 km. Symptoms include coolant warning light, engine overheating, or poor cabin heating. The part itself costs €230-400 due to the integrated electric design. Labor is significant (approximately 6 hours at dealer rates) due to accessibility, bringing total dealer cost to €900-1,200. Independent shops typically charge €600-800 total. This is a fairly common BMW cooling system issue. The water pump housing can also develop leaks from heat degradation.
Fuel injector failure (pre-Aug 2017)€500 - €2,500
Early B58 injectors can stick open, washing oil from cylinder causing piston damage · more· less
B58 cars built before August 2017 with injector part number 13537639990 can experience injector failures where they stick open. This causes excessive fuel to enter the cylinder, washing oil from piston rings (bore washing) or in severe cases causing cracked pistons and scored cylinder bores. Symptoms include rough idle, check engine light, misfires, and loss of compression. Replacing all 6 injectors costs €500-800 (aftermarket Bosch) or €1,300+ (BMW dealer). If piston/bore damage occurs, engine replacement may be needed (€5,000+). This issue prompted BMW to supersede the injectors (new part number: 13538625396). More common on cars running high-ethanol fuels. Affects completely stock cars.
Oil filter housing gasket leak€400 - €1,200
Gasket and plastic coolant hose degrade from heat, causing oil and coolant leaks · more· less
This is an extremely common oil leak on the B58. The oil filter housing gasket degrades over time, but on B-series engines the primary issue is often the brittle plastic coolant vent hose that runs near it. Intense engine heat degrades both components simultaneously over 60,000-80,000 km. A proper repair requires replacing the gasket set (€45), the plastic vent hose, and the single-use aluminum bolts all at once. Simple gasket-only replacement costs €150-300, but full proper repair runs €400-800 at independent shops or €800-1,200 at dealers (6.6 hours book time). On some B58s, the housing itself can break from heat exposure, requiring full housing replacement (€3,000 in extreme cases).
VANOS solenoid o-ring failure€250 - €600
Variable valve timing solenoid o-rings degrade from heat, causing oil leaks and performance loss · more· less
A repeat issue on many BMW engines including the B58. The VANOS solenoid o-rings degrade from heat and wear, allowing oil to seep through and disrupting valve timing actuation. Symptoms include sluggish acceleration, loss of power (especially below 3,000 RPM), rough idle, check engine lights with P or 2A82/2A87 fault codes, and ticking noises. The solenoids are "buried at the back" of the B58 making access more difficult than on the N55. Parts cost €80-150, labor €150-400 depending on shop. Can be cleaned as a temporary fix but replacement recommended. Failure typically occurs around 50,000-70,000 km, often caused by dirty oil or oil that has broken down.
PCV valve failure€250 - €500
Crankcase ventilation diaphragm ruptures, causing turbo failures and oil consumption · more· less
The PCV (positive crankcase ventilation) valve diaphragm can rupture or crack, rerouting crankcase gases incorrectly. This pumps oil-rich gases into the intake manifold. Symptoms include excessive oil consumption, check engine light, rough idle/stalling, oil leaks around engine seals, thick bluish exhaust smoke, and in severe cases turbo failures. BMW extended the warranty on PCV valves to 15 years or 150,000 miles after recognizing this as a widespread B58/B48 issue. Test by removing oil cap while engine runs - significant suction indicates bad PCV. Parts cost €50-150, labor €150-300. Can cause destructive engine damage if ignored. Should be replaced every 60,000 km as preventive maintenance.
Rear differential bushings€300 - €1,200
Three bushings (especially rear one) crack from stress on RWD performance cars · more· less
Common on higher-power RWD BMWs including the M140i. There are 3 differential bushings (2 front, 1 rear) and the rear one typically fails first. Symptoms include clunking noise from rear when letting off throttle, vibrations under throttle at low RPM, steering wheel shake above 70 km/h, and harsh rear suspension feel. Typical failure occurs around 35,000-60,000 km on performance models. Parts are relatively cheap but labor is extensive due to access requirements - total cost €300-500 at independent shops, €800-1,200 at dealers. Best to replace all 3 bushings while access is available. Also inspect front and rear guibos (driveshaft couplings) while working in that area.
Turbo wastegate rattle€100 - €2,500
Wastegate actuator develops play over time causing metallic rattle at low RPM · more· less
The turbo wastegate actuator can develop play over time, leading to a metallic rattling noise from the engine bay, particularly at low RPMs or during deceleration. This is more common on older or high-mileage B58s (100,000+ km) and more prevalent on tuned engines running higher boost. DIY repair kits cost €95-150 but require turbo removal, disassembly, and welding. BMW may address under warranty in some cases. More of an annoyance than serious issue, though performance can degrade if ignored. Some owners report BMW uses software updates to minimize rattle by adjusting wastegate positions, but this affects boost response.
Electric parking brake malfunction€200 - €800
EPB system sensitive to low battery voltage, actuators can fail from wear · more· less
The electronic parking brake (EPB) is voltage-sensitive and often triggers malfunction warnings when battery power drops. Can also fail due to actuator motor wear (built into rear calipers), sensor issues, or corroded wiring. Symptoms include "Parking Brake Malfunction" warning and inability to engage/release parking brake. Low battery is the most common cause - if car sits unused for extended periods, maintain battery charge. Actuator replacement costs €400-800 at dealers, €200-400 at independent shops. Can be reset with OBD-II tools (BimmerLink app) but underlying cause must be addressed. Ensure battery is fully charged before any reset procedure.
Reliable for a performance car, but maintenance-intensive
The B58 engine has an excellent reputation for reliability - significantly better than the N54 and N55 it replaced. Most issues are age-related wear items (gaskets, seals, bushings) rather than catastrophic failures. Carbon buildup is inevitable with direct injection and requires regular walnut blasting. Early cars (pre-Aug 2017) had injector issues but these are largely resolved on later examples. The ZF 8-speed automatic is generally bulletproof when properly maintained. Buy a well-maintained example with complete service history - many M140is have been driven enthusiastically.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete BMW dealer or reputable specialist records essential. Verify oil changes every 10,000-12,000 km or annually. Check for walnut blasting service if over 50,000 km.
Tires
Standard sizes: 225/40R18 front, 245/35R18 rear (staggered). Check tread depth, age (date codes), and uneven wear. Rear tires wear faster on RWD.
Cold start
Must start engine completely cold. Listen for unusual rattles, ticking, or rough idle in first 30 seconds.
Body condition
Check for accident damage, paint mismatch, rust. Inspect wheel arches and undercarriage.
Test drive
Minimum 20-30 minutes including varied speeds and conditions. Get transmission up to temperature.
Specific for this vehicle
Check for oil leaks around valve cover and oil filter housing
Look carefully at top of engine (valve cover) and left side (oil filter housing). Even small leaks indicate imminent gasket replacement needed.
Inspect coolant level and condition
Low coolant or frequent top-ups indicate water pump or oil filter housing gasket issues. Check for coolant warning messages in iDrive.
Listen for wastegate rattle on deceleration
Metallic rattle at low RPM or when letting off throttle indicates turbo wastegate actuator wear. More common on higher-mileage examples.
Test automatic transmission (if equipped)
Drive for 15+ minutes. ZF 8HP should shift smoothly. Harsh 1-2 or 2-3 shifts can indicate incorrect fluid level or old fluid. Ensure no clunking or hesitation.
Check rear differential for clunking
Pull handbrake to create drag, drive in reverse and slowly engage clutch, then do same in first gear. If clunk is present, differential bushings may be worn.
Verify crankshaft sensor recall completed (May-July 2018 cars)
Cars built between 16 May and 13 July 2018 had a crankshaft sensor issue recall. Contact BMW with VIN to verify completion.
Check VIN for early fuel injector (pre-Aug 2017)
Cars built before August 2017 may have old injector part number 13537639990. Ask if injectors have been replaced with updated version 13538625396.
Test all electronics including parking brake
Check iDrive, parking sensors, tire pressure monitoring, and electric parking brake operation. Ensure battery is healthy (low voltage causes EPB malfunctions).
Inspect for modifications and tuning
Many M140is are modified. Check for aftermarket exhausts, intakes, ECU tunes. Modifications can affect reliability and warranty. Avoid heavily modified examples unless comprehensively documented.
Review maintenance records for walnut blasting
Direct injection engines need intake valve cleaning every 50,000-70,000 km. If not done yet on higher-mileage car, budget €300-750 soon.
Recalls and Technical Service Bulletins
Crankshaft sensor issue (16 May - 13 July 2018)Verify completed
DME control unit recall (SI B12 01 19)Verify completed
PCV valve extended warranty (15 years/150,000 miles)May still apply
Fuel injector supersession (pre-Aug 2017 cars)Check if updated
Contact a BMW dealer with the VIN to verify all recalls have been completed. The crankshaft sensor recall is particularly important for mid-2018 production. Early cars (pre-August 2017) should ideally have had fuel injectors updated to the superseded part number.
Warranty Status
Factory warranty (4 years/80,000 km)Expired on all M140is
PCV valve extended warranty15 years or 150,000 miles
BMW Extended warranty availableFrom authorized dealers
All M140is (2016-2019) are now outside their original factory warranty. BMW offers extended warranty programs through authorized dealers - pricing varies by coverage level and vehicle condition. The PCV valve has an extended 15-year warranty due to widespread failures across B58/B48 engines. Consider extended warranty if buying a higher-mileage example (80,000+ km) as repair costs can be significant.
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.