2005-2011 · 3.0L M57 inline-6 diesel (231 hp / 241 hp LCI)
Exceptional diesel workhorse with one of BMW's most reliable engines ever built. The M57 engine won multiple International Engine of the Year awards and many examples exceed 200,000 miles with proper maintenance. Main concerns: swirl flaps can clog or fail on early cars (removal recommended), DPF regeneration issues from short trips, and both engine and EGR thermostats fail around 7 years. High-mileage examples with full service history are often safer buys than neglected low-mileage cars. The E90 generation itself has typical BMW wear items - differential oil leaks, suspension bushings, and oil filter housing gasket leaks.
Expected Annual Maintenance Costs
€900 - €1,650/year
15,000 km/year
Fixed costs
€500-850
Risk buffer
€400-800
What Can Break
bars = likelihood
Swirl flaps clogging or failure€400 - €1,200
Inlet manifold flaps clog with soot/oil, can stick closed causing power loss · more· less
The M57 engine uses swirl flaps in the intake manifold to improve low-speed air-fuel mixing. On the newer M57N2 in the E90, these are cartridge-type and less prone to catastrophic failure than older designs, but they still clog with soot and oil gunk over time. When stuck closed, the engine loses power and can cut out due to restricted airflow. Many specialists recommend complete removal with blanking plates (€400-600 parts and labor) rather than replacement. If the intake manifold needs replacing due to damage, cost is €440-800 for parts plus 4-6 hours labor.
DPF clogging and regeneration failure€800 - €2,000
Diesel particulate filter blocks, especially with short trips or failed thermostats · more· less
The DPF requires regular regeneration cycles where exhaust temperature reaches 600°C+ to burn off accumulated soot. This needs at least 1/4 tank fuel, 20-30 minutes driving above 65 km/h, and proper engine temperature. Failed thermostats (common at 7 years) prevent the engine reaching temperature, blocking regeneration. Short trips and gentle driving accelerate clogging. Professional DPF cleaning costs €300-600, but if too clogged, replacement is €1,200-2,000. DPF removal is illegal in EU and causes MOT failure. Back pressure sensors (€100-200) can also fail and prevent regeneration.
Turbocharger failure€1,200 - €2,500
Turbo develops oil leaks or bearing wear, typically after 150,000 km on neglected cars · more· less
While the M57 turbocharger is generally robust, failures occur from oil contamination (failed breather system), lack of warm-up/cool-down, or extended oil change intervals. Symptoms include white smoke on startup, blue smoke under acceleration, oil in intercooler pipes, or loud whistling/grinding sounds. Turbo actuator can stick from carbon buildup on cars driven gently (repair €500-600 at specialists vs €1,500+ dealer replacement). Full turbo replacement costs €1,200-1,800 for remanufactured units, €2,000-2,500 for new OEM at dealers. Prevention: change oil every 10,000 km max, use quality oil, allow warm-up and cool-down.
Thermostat failures (engine + EGR)€250 - €600
Both main and EGR thermostats fail around 7 years, causing cold running and DPF issues · more· less
The E90 uses dual thermostats - main engine thermostat and EGR cooler thermostat. Both typically fail around 7 years regardless of mileage. Failed thermostats cause engine to run cold, preventing DPF regeneration, increasing fuel consumption, and accelerating engine wear. Symptoms: no temperature rise, poor cabin heating, DPF warning lights. Parts cost €70-120 per thermostat. Labor is 2-3 hours total if done together (highly recommended). Many specialists recommend replacing both preventatively at 7 years or when buying a car of this age. Total cost €250-400 at independent specialists, €450-600 at BMW dealers.
Fuel injector failure€1,000 - €2,500
Injectors fail or leak internally, causing rough running and starting issues · more· less
M57 diesel injectors cost €250-350 each and commonly fail between 150,000-200,000 km. Symptoms: lumpy idle (especially when cold), misfires, hard starting, white smoke, fuel smell. Diagnosis requires BMW diagnostic software (INPA) to check "smooth running controller error" showing over/under-fueling cylinders. The challenge: injectors seize into cylinder head from corrosion. Dealers charge up to 2.5 hours labor per seized injector, using techniques from Coca-Cola soaking to drilling out. A single injector replacement runs €600-900, multiple injectors €1,500-2,500. Some owners report complete engine replacement quotes (€3,500+) when compression issues compound injector problems.
EGR cooler failure and fire risk€450 - €1,800
EGR cooler can leak internally, mixing coolant with soot creating fire risk · more· less
BMW recalled 2013-2018 diesels for EGR cooler fire risk, but issue affects earlier cars too. When EGR valve sticks open from carbon buildup, coolant can mix with hot diesel soot creating smoldering embers. These can melt the plastic intake manifold and cause engine fires. Warning signs: coolant loss, unusual exhaust smell, smoke from engine bay, power reduction. EGR valve replacement costs €250-400. EGR cooler replacement €450-750. If intake manifold melts, add €800-1,200. Worst case with turbo damage: €4,000-6,000. Many specialists recommend EGR delete/blanking (not legal for road use in EU) or at minimum regular EGR valve cleaning every 60,000 km.
Oil filter housing gasket leak€150 - €600
Common E90 issue - housing gasket dries out causing oil weeping · more· less
The oil filter housing gasket is the most common leak point on all E90 models. The gasket dries, shrinks, and allows oil to weep past. This is purely age-related and affects most E90s over 10 years old. DIY parts cost only €25-40 (includes gasket, bolts, pressure switch) and takes under 1 hour with basic tools - no intake manifold removal needed despite what BMW manual states. Dealer quotes run €400-600 with unnecessary procedures. Independent specialists charge €150-250. Also consider replacing the aluminum coolant flange (€18) at same time as the OEM plastic version is a common failure point. This is preventive maintenance every E90 owner should budget for.
Clutch and dual-mass flywheel (manual)€800 - €1,500
Typically lasts 150,000+ km but must replace both clutch and DMF together · more· less
The 330d uses a dual-mass flywheel (DMF) which cannot be machined - if surface is damaged, full replacement required. Failure symptoms: gear lever/clutch pedal pulsing, vibrations, tractor-like noise. Clutch typically lasts 150,000-200,000 km with proper use (city driving reduces life). When replacing, must do clutch disc, pressure plate, release bearing, pilot bearing, and DMF together. Parts cost €370-600 for quality aftermarket kits (Sachs, LUK). Labor is 4-6 hours. DIY possible for experienced mechanics. Independent specialists: €800-1,100 total. BMW dealers: €1,200-1,500. Budget this as a wear item at high mileage.
Rear differential oil leak€350 - €1,300
E90 differentials leak more than E46 generation - seals fail causing whining · more· less
The E90 rear differential has a higher failure rate than previous generation. Most common: output shaft seals (€30 parts) and pinion seal (€20 parts) leak as they age. Symptoms: differential oil puddles under car, whining/howling noise (means dangerously low oil - immediate attention needed). If caught early: seal replacement costs €350-500 at independent shops, €900-1,300 at dealers. If driven until diff runs dry: complete differential replacement €1,500-2,500. Prevention: differential oil change every 60,000-80,000 km (not in BMW service schedule but highly recommended). Check for leaks at every service. Some owners report differential failures from 120,000 km onwards.
Water pump failure€400 - €900
Mechanical water pump fails typically around 130,000-160,000 km · more· less
The 330d uses a mechanical (belt-driven) water pump unlike the electric pumps on petrol E90s. Common failure points: bearing wear causing whining noise, seal leaks, impeller damage. Symptoms: coolant leaks down right side of engine, overheating, coolant warning light. Recommended replacement interval: 130,000-160,000 km preventatively. Parts cost €180-300 for quality aftermarket (Hepu, Graf), €350-500 for OEM. Labor 3-4 hours. Often replaced with thermostat since access is similar. Independent specialist: €400-600 total. BMW dealer: €700-900. Also inspect coolant hoses and expansion tank while pump is off - these also fail from age.
Front suspension bushings and control arms€400 - €1,000
Bushings wear from 110,000 km causing clunking, vibration, and loose handling · more· less
E90 front control arm bushings and ball joints typically wear out around 110,000-130,000 km. Symptoms: clunking over bumps, vibration through steering wheel, loose/sloppy handling, sudden jerk forward when stopping, uneven tire wear. BMW integrated bushings into control arms for easy replacement. Aftermarket upgrade kits (TRW M3-style) cost €330-450 for complete front refresh. OEM arms €500-700. Labor 3-4 hours. M Sport suspension wears faster due to stiffer setup. Independent specialists: €600-800 total. Dealers: €900-1,200. Also check rear upper control arms (€250-400 when needed). Run-flat tires accelerate suspension wear - many owners switch to standard tires for comfort and longer suspension life.
Alternator failure€400 - €800
Alternator slowly fails causing battery drain, dimming lights, and electrical issues · more· less
Alternator failure symptoms appear gradually: battery light on dashboard, dimming instrument panel/headlights, flickering radio, window operation causing lights to dim. Should measure 13.5-14.6V with engine running - below this indicates alternator or voltage regulator failure. Failed alternator diodes can drain battery when engine is off. E90 330d also has Intelligent Battery Sensor (IBS) on negative terminal that can malfunction, preventing sleep mode. Parts: remanufactured alternator €350-500 (includes core charge refunded when old unit returned), new OEM €600-700. Labor 2-3 hours. Independent specialists: €400-600 total. Dealers: €700-800. Important: alternators have different amperage ratings - ensure replacement matches original.
Reliable engine, but aging platform requires attention
The M57 engine is exceptionally reliable and capable of very high mileage with proper maintenance. However, the E90 platform itself (2005-2011) is now 13-19 years old, so expect typical age-related issues: rubber seals, thermostats, suspension bushings, and differential seals. Buy on service history and condition, not mileage - a well-maintained 200,000 km example is often better than a neglected 100,000 km car. Budget €1,000-1,500/year for a high-mileage example, less for recently serviced cars.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete BMW dealer or specialist records essential. Verify oil changes at 10,000 km intervals maximum (not BMW's 25,000 km CBS intervals). Look for thermostat replacements around 7 years.
Tires
Check tread depth, age (date codes), uneven wear (indicates suspension issues). Many owners replace run-flats with standard tires for better comfort.
Cold start
Engine must start completely cold. Listen for unusual noises, check for excessive smoke (white or blue indicates turbo/injector issues).
Extended test drive
Minimum 30 minutes including motorway speeds to fully warm engine and check DPF regeneration ability. Feel for transmission smoothness, turbo response.
Specific for this vehicle
DPF regeneration check
Use diagnostic tool (INPA/ISTA) to check DPF loading percentage and last regeneration. Above 85% loading indicates problem. Check for fault codes related to DPF, thermostats, or back pressure sensor.
Oil leaks inspection
Check oil filter housing, valve cover gasket, turbo oil feed lines, and rear differential. Small weeps are normal on old E90s but active drips need immediate repair.
Swirl flaps check
Ask if swirl flaps have been removed/blanked. If not, check for hesitation, power loss, or rough running. Consider budgeting for removal (€400-600).
Thermostat test
Monitor engine temperature gauge during test drive. Should reach 90°C within 10-15 minutes. If stays cold, both thermostats likely failed.
Turbo inspection
Check for oil in intercooler pipes (remove intake pipe - should be dry). Listen for whistling or grinding from turbo. Check for play in turbo shaft (requires removal of intake).
Injector smoke test
White smoke on cold start or blue smoke under hard acceleration indicates failing injectors or turbo. Use diagnostic software to check injector balance values.
Suspension clunk test
Drive over speed bumps slowly - listen for clunking from front or rear. Check for excessive body roll. Worn bushings are common after 110,000 km.
Differential noise check
Listen for whining or howling from rear, especially during acceleration. Check under car for differential oil leaks or wetness.
Cooling system pressure test
Have specialist perform cooling system pressure test. Check expansion tank, water pump, and all hoses for leaks. Look for coolant residue on engine.
Gearbox condition (manual)
Clutch should engage smoothly without judder. Check for DMF noise (rattling at idle, especially when clutch pedal depressed). All gears should engage cleanly.
EGR cooler fire risk (some diesel models)Check eligibility
Contact BMW with your VIN to verify all recalls completed. The Takata airbag recall is particularly important. Check BMW's official recall checker or contact your local BMW dealer. Technical Service Bulletins (TSBs) are not mandatory recalls but document known issues and solutions - ask dealer about applicable TSBs for your specific VIN.
Warranty Status
Factory warranty (2 years)Expired on all E90s
Extended warranty (third-party)€400-800/year available
All E90 330d models are now outside their original factory warranty. Third-party extended warranties are available through various providers (Warranty Wise, AA, RAC in UK; similar providers in Netherlands/Germany). Read exclusions carefully - many exclude DPF issues, oil leaks, and age-related wear items. Given the E90's age, setting aside €100-150/month in a personal "repair fund" is often more cost-effective than warranty premiums.
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.