2010-2017 · 2.0L 4-cylinder diesel (N47/B47) · 184-190 hp
Popular executive diesel with good fuel economy (45+ mpg real-world) and solid performance. Major concern: N47 engine (2010-2013) has notorious timing chain at rear of engine that can fail catastrophically between 60,000-120,000 km, requiring full engine removal to fix (€2,500-6,500). Post-March 2011 N47 engines improved but not immune. From 2014, BMW switched to far more reliable B47 engine with timing chain at front. Other issues: DPF problems on short journeys, EGR failures, turbo actuator sticking, water pump at 80,000+ km, injector failures. Avoid 2010-early 2011 cars unless timing chain professionally replaced.
Chain at rear of engine stretches, causes rattling, eventual catastrophic failure · more· less
The N47 engine (2010-2013) is notorious for timing chain failure due to poor design - the chain is mounted at the rear of the engine near the firewall. Symptoms include metallic rattling from rear of engine, especially on cold starts or when cranking. Many owners report non-start issues after brief stops (e.g., refueling). When the chain snaps, valves collide with pistons causing massive damage: bent valves, damaged pistons, broken camshafts. Pre-March 2011 engines most affected, with failures occurring between 40,000-120,000 km. Mid-2009 and March 2011 updates reduced but didn't eliminate failures. Replacement requires complete engine removal (30-45 hours labor), costing €2,500-4,000 for preventive replacement or €4,000-6,500 if chain has already failed and caused damage. Some specialists report €1,000-1,500 for replacement before failure. Critical: Regular oil changes every 6,000-8,000 km (not BMW's 18,000 km interval) significantly reduce risk. 2014+ B47 engine solved this issue by moving chain to front of engine.
DPF clogging and regeneration issues€1,000 - €2,500
Diesel particulate filter blocks from short trips, city driving · more· less
520d models are notorious for DPF problems when driven mainly on short journeys or stop-start city driving. The DPF requires temperatures above 600°C and sustained driving at 40+ mph for 20-30 minutes to regenerate. Warning signs include loss of power, rough running, excessive regeneration attempts (noticeable as engine running hotter/louder when parked). If DPF becomes too blocked, the car enters limp mode and won't regenerate naturally. Professional DPF cleaning costs €450-650, while complete replacement is €1,500-2,500. Prevention: Regular highway runs at 75-80 mph for 45+ minutes. At 100,000 km, carbon buildup throughout intake system (EGR cooler, inlet manifold, swirl flaps, intake valves) often requires manual cleaning by removing inlet manifold and walnut blasting valves (€800-1,200). Fault codes 480A and 481A prevent regeneration until cleared. Not suitable for buyers who only make short urban trips.
EGR cooler and valve failure€600 - €1,500
Carbon buildup causes EGR sticking, cooler leaks, loss of power · more· less
The EGR (Exhaust Gas Recirculation) system on the 520d is prone to carbon buildup and cooler leaks. Symptoms include loss of power, black smoke, rough idle, and check engine light. There have been EGR recalls on some F10 models, but post-recall, new problems often emerge as loosened carbon travels downstream and clogs swirl flaps in the inlet manifold, causing no boost. EGR valve replacement costs €400-700 at specialists. Complete EGR cooler replacement at BMW dealer runs €1,200-1,500. The entire EGR system (cooler, feed line, inlet manifold, swirl flaps) becomes carboned up by 100,000 miles and benefits from manual de-carbonization. Using quality diesel fuel and regular Italian tune-ups (sustained high RPM highway driving) helps prevent buildup. Some owners opt for EGR delete/blanking, though this affects emissions compliance.
Turbocharger actuator failure€500 - €2,500
Actuator sticks from carbon buildup, causes limp mode and EPC light · more· less
The turbo actuator tends to stick if the car is driven too gently or only for short trips, as carbon builds up and seizes the mechanism. Symptoms include EPC warning light, loss of power, and limp mode. BMW won't sell the actuator separately from the turbocharger. Actuator-only repair at specialists costs €500-700, but if turbo internals are damaged from prolonged running with stuck actuator, full turbo replacement runs €1,200-2,500 (parts €500-1,000, labor €700-1,500). Expected turbo lifespan is 120,000-180,000 km with proper maintenance. Using premium diesel fuel and regular spirited driving helps prevent actuator sticking. If turbo replacement becomes necessary, aftermarket options from FCP Euro (€960) or rebuilt units (€1,400) offer significant savings over BMW dealer turbos (€2,700+).
Water pump and thermostat failure€800 - €1,300
Electric water pump fails around 80,000-100,000 km, causes overheating · more· less
The F10 520d uses an electric water pump that commonly fails between 80,000-100,000 km. Symptoms include coolant warning light, engine overheating, or poor cabin heating. The pump is integrated with the thermostat housing, so both should be replaced together. Complete replacement at independent specialists costs €800-1,200 (parts €450-550, labor €350-650). BMW dealer charges €1,200-1,500. Failure can leave you stranded, so many owners replace proactively at 80,000 km. Also replace the U-shaped coolant hose at same time (€20-50). Genuine BMW pump costs €500+, aftermarket quality units €200-350. Budget also for new coolant (€50-80) and potentially coolant reservoir cap. DIY possible if mechanically inclined, with parts costing €400-500 total. Being proactive prevents catastrophic overheating and potential head gasket damage.
Injector failure and leaks€400 - €2,500
Injectors leak diesel, cause rough running, can damage ECU · more· less
Both N47 and B47 engines experience injector failures, typically caused by wear from poor fuel quality or carbon buildup. Symptoms include rough idling, misfires, excessive black smoke, reduced fuel economy, and engine warning lights. Critical issue: The ECU is located near the injectors, and fuel leaks can seep into the ECU compartment causing short circuits and electronic failure. Single injector replacement costs €200-400 (part €100-200, labor €100-200), but replacing all four injectors runs €800-1,600. If injector leak damages the ECU, repair/refurbishment costs €400-800 or replacement €1,500-2,500. After injector replacement, new injector codes must be programmed into ECU (€50-150). Prevention: Use premium diesel fuel and add injector-cleaning additives regularly. Check for diesel smell in engine bay and fumes around injectors. High-mileage cars may need all injectors replaced as preventive maintenance.
Front suspension thrust arm bushings€400 - €900
Rubber bushings wear out, cause wheel shimmy and poor handling · more· less
F10 models are prone to front thrust arm bushing failure - BMW treats these as maintenance items. Symptoms include wheel shake/shimmy while driving (especially when braking), clunking from front end, vague steering, vibrations, and DSC light cycling on/off. In severe cases, the ball joint can separate completely, causing total loss of steering control. BMW bushings are flexible rubber that deteriorates with age and mileage, typically failing between 60,000-100,000 km. Front thrust arms replacement costs €400-600 at independent specialists (parts €200-300, labor €200-300), or €700-900 at BMW dealers. Upgrade options include Powerflex polyurethane bushings (€150-250) which last longer and improve handling precision, though they transmit more road noise. Ball joints should be inspected annually and replaced every 3-4 years. Budget for both control arms and thrust arms if doing full front suspension refresh (€800-1,400 total).
Glow plug and controller failure€200 - €600
Hard starting in cold weather, extended pre-heat time · more· less
Glow plugs aid cold starting on diesel engines. Individual glow plug failure causes hard starting, rough idle when cold, white smoke on startup, and increased pre-heat time. The glow plug control unit can also fail, typically triggering fault codes. Individual glow plugs cost €15-25 each (Bosch, Swag), with set of 4 around €60-100. Labor for replacement is €100-200. Complete glow plug control unit costs €150-250 for OEM part, plus €100-150 labor. Total cost for replacing all 4 glow plugs and controller if both needed: €400-600. Testing glow plug resistance without removal is possible to diagnose which has failed. Many specialists recommend replacing glow plugs only when they fail rather than as preventive maintenance. Most commonly fails in higher mileage cars (150,000+ km) or in cold climates.
High-risk N47 timing chain, budget for DPF and diesel maintenance
The F10 520d can be reliable with proper maintenance, but the N47 engine (2010-2013) has serious timing chain issues that make pre-2011 cars risky purchases. Post-2014 B47 models are significantly more reliable. All diesel maintenance items (DPF, EGR, injectors, turbo) require attention. Best for high-mileage motorway driving, not urban short trips. Budget €500-1,000 annually for diesel-specific repairs beyond basic servicing.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete BMW dealer or specialist records essential. Verify oil changes every 6,000-10,000 km (not 18,000 km). Look for evidence of timing chain replacement on N47 engines.
Tires
Check tread depth, age (date codes), and uneven wear. 225/55R17 is common size. Expect €800-900 for set of 4 including fitting.
Cold start - CRITICAL
Must start engine completely cold. Listen carefully for timing chain rattle from rear of engine in first 30 seconds. Any rattle is serious concern.
Test drive
Minimum 30 minutes including highway speeds. Feel for steering vibration, wheel shimmy, suspension clunks. Ensure DPF regeneration cycle can complete.
Undercarriage inspection
Check for diesel leaks around injectors, oil leaks from timing chain area, coolant leaks from water pump.
Specific for this vehicle
Timing chain rattle test (N47 engines)
Start engine completely cold and listen for metallic rattling noise from rear of engine near firewall. Rattle lasting more than 1-2 seconds indicates wear. Rattle lasting 10+ seconds is critical. Also test starting immediately after brief stop (simulates refueling). Non-start or extended cranking indicates chain tension loss. This is the single most important check.
Check build date and engine code
Confirm whether car has N47 (2010-2013) or B47 (2014-2017) engine. Pre-March 2011 N47 engines highest risk. Post-March 2011 improved but still vulnerable. B47 from 2014 onward significantly more reliable. Check for evidence of timing chain already replaced (look for recent major engine work in service history).
DPF regeneration and soot level check
Use diagnostic tool to check DPF soot loading percentage (should be below 40%). High soot level indicates car driven mostly short trips or DPF not regenerating properly. Check for fault codes 480A, 481A (prevent regeneration). Test regeneration by driving at 75-80 mph for 30+ minutes on highway - engine should run hotter and you may notice smell from exhaust. Ask seller about typical journey patterns.
EGR and intake system inspection
Check for black sooty deposits around EGR valve and inlet manifold. Check for oil/carbon buildup in intake pipes. Look for EPC warning light or loss of boost during test drive. Remove oil filler cap with engine running - excessive blow-by indicates worn piston rings. Check service history for EGR recalls completed.
Turbo operation and boost check
Test full-throttle acceleration from 2,000 rpm in 3rd gear. Turbo should spool smoothly without hesitation, smoke, or whistling. Check for blue/grey smoke on hard acceleration (indicates turbo seal wear). Test for EPC warning light. Listen for actuator clicking or grinding noises.
Coolant system check
Check coolant level and condition (should be pink/red, not brown or milky). Look for leaks around water pump area. Start cold and check cabin heater - poor heating indicates water pump or thermostat issues. Check coolant warning light operation. Ask when water pump last replaced (should be done by 100,000 km).
Injector leak inspection
Open hood and smell for diesel fumes around engine (indicates injector leak). Check for black deposits or diesel residue around injector seats. Look for rough running, misfires, excessive black smoke. Check service history for injector replacement. Injector leaks can damage the nearby ECU.
Front suspension and steering check
Test for wheel shimmy/vibration at 50-70 mph, especially under braking. Jack up front and check for play in thrust arm bushings and ball joints. Turn steering full lock both ways and drive slowly - listen for clunking or creaking. Check tire inner edges for uneven wear (indicates worn bushings/alignment issues).
Brake system inspection
Check brake pad thickness front and rear. Test brake feel - should be firm, not spongy. Check for vibration under braking (warped discs). Original discs last 60,000-80,000 km. Budget €600-1,000 for full brake replacement at independent shop.
Recalls and Technical Service Bulletins
Timing chain (N47 pre-March 2011)Extended warranty, check if replaced
VANOS adjustment unit oil leakage (2009-2011)Recall 14V-176 (N51/N52 petrol only)
EGR system software updateCheck with BMW using VIN
Contact BMW dealer with the VIN to verify all recalls and TSBs completed. Most critical: Check if N47 timing chain has been replaced. BMW extended warranty on pre-2011 N47 timing chains but many cars still at risk. Use NHTSA database or BMW official recall checker for complete list.
Warranty Status
Factory warranty (2 years)Expired on all F10 models
N47 timing chain extended warrantyCheck eligibility with BMW
BMW Extended WarrantyAvailable, check terms and cost
All F10 520d models are outside original factory warranty. BMW offered extended warranty coverage on N47 timing chain issues for affected vehicles - check eligibility. Extended warranty available through BMW dealers but expensive and may exclude common diesel issues (DPF, injectors). Independent warranty providers offer alternatives but read terms carefully regarding pre-existing conditions and exclusions.
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.