The entry-level diesel in BMW's third-generation 1 Series, built on the front-wheel-drive UKL2 platform shared with the 2 Series Gran Coupe F44 and X1 F48. The B37 three-cylinder turbodiesel is a compact, efficient unit that delivers strong fuel economy for commuters and motorway drivers. It pairs with either a 6-speed manual or the Getrag 7DCT300 dual-clutch automatic. Replaced by the F70 generation in late 2024.· more· less
Excellent fuel economyLow insurance and running costs
DPF clogs on short tripsDKG gearbox jerky when cold
Buy if: You want an efficient premium diesel hatchback for motorway commuting and can verify complete service history with regular oil changes.
Avoid if: You mostly drive short urban trips (DPF clogging and EGR issues will follow) or want a refined and quiet powertrain (three-cylinder vibration is noticeable).
Price & maintenance
Used price
€17,400
median asking price, typically 85,000 km
Typical range€15,000 – €18,700
Kilometres drivenAll
Maintenance cost
€750 – €1,400/year
at 15,000 km/year
Fixed costsservice, tyres, brakes€500 – €850 /yr
Risk bufferunplanned repairs€250 – €550 /yr
Price estimates are based on German asking prices. Prices and costs vary by vehicle condition and location.
Ownership costs
Maintenance assumes 15,000 km a year. Price estimates are based on German asking prices. Prices and costs vary by vehicle condition and location.
Diesel particulate filter fails to regenerate on frequent short journeys, eventually blocking completely · more· less
The B37 diesel relies on periodic DPF regeneration cycles that require sustained driving at highway speeds for at least 20 minutes. Cars used primarily for short urban trips (under 10 km) never reach the exhaust temperatures needed for passive regeneration. Soot loading builds progressively. At around 60-70% loading, warning lights appear and performance drops. If ignored, soot loading reaches 75%+ where forced regeneration at a dealer is needed (€150-300). If the DPF becomes fully blocked or develops micro-cracks from repeated failed regeneration attempts, replacement costs €1,200-1,800. Prevention is straightforward: drive at motorway speed for 20+ minutes at least once a week. This issue affects all small diesel engines, not just the B37, but is particularly relevant for the 116d because many are purchased as city cars.
EGR valve and cooler carbon buildup
€400 - 1,2002 of 7
Exhaust gas recirculation system accumulates carbon deposits, reducing engine performance and triggering warning lights · more· less
The EGR system recirculates exhaust gases to lower emissions, but carbon deposits gradually build up on the valve and cooler over time. This is accelerated by short-trip driving patterns where the engine runs cool. Symptoms include rough idle, loss of power, increased fuel consumption, and the engine management light illuminating. An EGR valve cleaning costs €200-400 at an independent specialist. If the valve is seized or the cooler has failed (internal coolant leak), replacement runs €600-1,200 including labour. Note: the major EGR cooler fire risk recall affecting 800,000 BMW diesels applies to N47, N57, and B47 engines only, not the B37. However, the B37's EGR components still deteriorate with age and low-quality use patterns.
Getrag 7DCT300 dual-clutch exhibits jerky low-speed behaviour and software faults · more· less
The 7-speed Getrag dual-clutch gearbox used in the 116d automatic can exhibit jerky behaviour at low speeds, particularly when cold. The gearbox takes considerable time to reach its operating temperature of 75-80 degrees Celsius, and until then, shifts can feel rough and abrupt. BMW issued a software recall for the DKG control unit on F40/F44 models to address OBD compatibility issues and improve shift quality. More seriously, neglecting the recommended gearbox oil service at 70,000 km can lead to clutch pack wear and dashboard warnings. A transmission fluid change costs €200-300 and significantly improves smoothness. If the mechatronic unit or clutch pack fails, repair costs range from €1,500 to €2,000. Manual gearbox models are not affected by this issue.
Turbocharger failure
€800 - 2,2004 of 7
Turbo can fail from oil starvation or foreign object damage, typically after 100,000+ km · more· less
The B37's turbocharger is generally reliable but can fail if oil change intervals are stretched too far or if oil quality is poor. Oil starvation causes bearing wear, eventually leading to excessive shaft play, oil smoke from the exhaust, and loss of boost. Symptoms include a whining or whistling noise that changes with engine speed, blue or grey exhaust smoke, and reduced power. A reconditioned turbo fitted at an independent specialist costs €800-1,200. A new OEM turbo from BMW with fitting runs €1,600-2,200. The B37's turbo operates at relatively modest boost levels (116 hp tune), which places less stress on the unit compared to higher-output variants. Regular oil changes with BMW-approved 5W-30 diesel oil are the best prevention.
AdBlue/NOx sensor malfunction
€400 - 1,0005 of 7
NOx sensor fails or AdBlue system triggers warnings, potentially preventing engine start after countdown · more· less
The B37 diesel uses an SCR system with AdBlue injection to meet Euro 6 emissions standards. The NOx sensor monitors exhaust gases and controls AdBlue dosing. When it fails, the system may display incorrect AdBlue level readings, trigger emissions warnings, and in some cases initiate a start-prevention countdown (typically 2,400 km before the engine will not restart). A faulty NOx sensor replacement costs €400-700 including diagnostics and coding. The AdBlue pump or injector can also fail, adding €300-500 to the repair. Using genuine AdBlue from a reputable source and keeping the tank above 25% helps prevent issues from crystallisation in the injector nozzle.
Oil filter housing gasket leak
€250 - 6006 of 7
Plastic oil filter housing develops leaks as gaskets age, causing oil drips · more· less
A common issue across BMW's modular engine family (B37, B38, B47, B48). The plastic oil filter housing uses rubber gaskets that harden and shrink with heat cycling over time. Oil begins to seep and eventually drip, typically appearing as wet spots around the housing or oil residue on the underside of the engine. The gasket itself costs €20-40, but labour to access and replace it runs €200-500 depending on the shop. If ignored, the leak worsens and can eventually cause low oil level warnings. This is a straightforward repair at any BMW-experienced independent garage.
iDrive 7 software glitches
€0 - 3007 of 7
Infotainment system occasionally freezes or reboots, primarily on early 2019-2020 production cars · more· less
Some F40 owners report the iDrive 7 system randomly restarting while driving, temporarily losing navigation, audio, and parking sensor functionality. The issue is most common on early 2019-2020 production cars and has largely been addressed through subsequent software updates. BMW released an audio module recall for delayed warning sounds on early production cars. Most instances can be resolved with a software update at the dealer (free under recall) or via over-the-air update. In rare cases, the head unit needs replacement at €200-300. A manual reset by holding the volume knob for several seconds typically resolves temporary freezes.
Reliable diesel when driven appropriately, but demands longer journeys
The B37 three-cylinder diesel is fundamentally sound with a warranty claim rate below the industry average for diesel engines. The biggest ownership risk is usage pattern rather than design defect: short-trip city driving causes DPF clogging and EGR carbon buildup, which together account for the most common and expensive repair bills. Motorway commuters who maintain regular service intervals report trouble-free ownership well beyond 150,000 km. The DKG automatic adds a layer of complexity that manual gearbox cars avoid entirely. With proper driving habits and timely maintenance, the 116d F40 is one of the more dependable small diesels in its segment.
Service history
Complete BMW dealer or specialist records essential. Verify oil changes every 15,000 km or 12 months maximum.
Tires
Check tread depth, date codes, and wear patterns. Run-flat tires (if fitted) wear faster and cost more to replace.
Cold start
Engine must be completely cold for this test. Listen for any rattling or unusual sounds in the first 30 seconds.
Test drive
Drive for at least 20 minutes including urban traffic and motorway speeds to check gearbox behaviour and DPF regeneration.
Specific for this vehicle
Check DPF status with diagnostic scan
Use an OBD reader (Carly, BimmerCode) to check DPF soot loading percentage and regeneration history. Soot levels above 50% or infrequent regeneration cycles indicate predominantly short-trip use.
Test DKG gearbox at low speeds (automatic models)
Drive through slow traffic and parking manoeuvres. Feel for excessive jerkiness, hesitation, or clunking when shifting between 1st and 2nd gear. The gearbox should smooth out once warm.
Check for AdBlue warnings or low fluid level
Verify the AdBlue tank is adequately filled. Check the dashboard for any emissions-related warnings or start-prevention countdown messages.
+ 3 more checksShow less
Look for EGR-related error codes
A diagnostic scan revealing EGR-related fault codes indicates carbon buildup. Also check for rough idle or hesitation during acceleration, which can signal a clogged EGR valve.
Inspect for oil leaks around filter housing
Check the oil filter housing area for wet spots or oil residue. This is a common leak point on B37 engines and worsens if ignored.
Verify iDrive software version is current
Check that the iDrive 7 system has received all available software updates. Early 2019-2020 cars may still run older software with known bugs.
Recalls and Technical Service Bulletins
DKG gearbox control unit software update (F40/F44 with 7-speed dual-clutch, production up to March 2021)Verify completed
Driver airbag deployment defect (selected early 2019-2020 production F40 models)Critical - verify completed
Audio module software - delayed warning sounds for PDC and seatbelt (early 2019-2020 production)Verify completed
Contact a BMW dealer with the VIN to verify all recalls and service actions have been completed. The driver airbag recall is safety-critical and must be confirmed. The DKG gearbox software update is important for automatic models built before March 2021.
Warranty Status
Factory warranty (3 years from Nov 2016)Expired on 2019-2021 models, may remain on late 2023 cars
Rust perforation warranty (12 years)Active on all F40 models
Extended warranty (BMW Extended Warranty)Available through BMW dealers, 1-2 year extensions
BMW introduced a 2+1 year warranty (3 years total, no km limit) from November 2016 for EU-delivered cars. Most used 116d F40 models from 2019-2021 will be outside their factory warranty. If considering a 2023 or later car, check remaining coverage with BMW using the VIN.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
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.
