BMW's first compact hatchback with a 2.0-litre petrol engine, offering rear-wheel drive and a premium driving experience in a smaller package. The 118i sits above the 116i and uses two different engines: the N46 with Valvetronic (2005-2007) and the direct-injection N43 (2007-2011 in most Western European markets). Both are capable engines but bring their own specific concerns that buyers need to understand.
Engaging rear-wheel-drive dynamics
Widely available, affordable parts
Engine-specific weak points (both)
Rear subframe prone to corrosion
Buy if: You find a well-maintained example with complete service history and can identify which engine is fitted to understand its specific risks.
Avoid if: You hear cold-start rattling, see warning lights on the dashboard, or cannot verify whether critical service items have been addressed.
Expected Annual Maintenance Costs
Common Problems
Plastic chain guides deteriorate and tensioner loses pressure, causing cold-start rattle and risk of engine damage · more· less
Both the N46 and N43 engines use a timing chain with plastic guides that degrade over time. On the N46, the chain guides become brittle from heat cycling and can fragment, with debris falling into the oil pan and potentially blocking the oil pump strainer, causing oil starvation. The tensioner bleeds off pressure overnight, resulting in a metallic rattling noise for 1-30 seconds on cold start. This typically surfaces between 80,000 and 130,000 km. On the N43, the issue is similar but the chain tends to stretch more aggressively. Independent specialists charge approximately €800-1,200 for a complete chain, guides, tensioner, and sprocket replacement. If the chain has skipped teeth or caused engine damage, a replacement engine costs €2,000-2,500 installed.
Valvetronic system degrades causing rough idle, reduced power, and engine warning lights · more· less
The N46 engine (2005-2007) uses Valvetronic variable valve lift, which the N43 does not have. The eccentric shaft sensor can leak oil past its seal, corrupting the connector and signal. The Valvetronic motor itself can overheat, and the eccentric shaft develops wear spots that cause binding. Return springs are also known to break. Symptoms include erratic idle, reduced power, and engine management warning lights. The eccentric shaft sensor costs approximately €100-150 for the part, with about 1 hour labor (€200-350 total). If the motor or eccentric shaft needs replacement, costs reach €600-1,500 at an independent specialist due to extensive labor. This issue typically manifests between 100,000 and 150,000 km.
Piezo direct injectors fail causing misfires, rough running, and cascading ignition coil damage · more· less
The N43 engine (2007-2011 in most Western European markets) uses high-pressure piezo direct injectors that are expensive and failure-prone. When an injector fails, it causes misfires that foul the spark plugs, which then overload and damage the ignition coils. This creates a cascade of failures that makes diagnosis confusing. New OEM injectors cost approximately €200-300 each, plus ECU coding. Replacing all four injectors with new plugs and coils at an independent specialist runs €800-1,500. This issue typically appears between 80,000 and 150,000 km. The N46 engine uses conventional port injection and is not affected.
NOx sensor degrades causing unstable idle, increased fuel consumption, and emission faults · more· less
The N43 engine has a NOx sensor for its lean-burn direct injection system. This sensor is prone to failure, causing unstable engine speed, increased fuel consumption, and persistent fault codes. Symptoms include hesitation on acceleration and rough idle. The sensor is manufactured by Continental and OEM replacement is recommended as aftermarket alternatives often do not work correctly. The sensor costs approximately €300-400, with about 1 hour labor. Some owners use a NOx emulator (€100-150) as a workaround, but this disables the lean-burn function and may not pass emissions testing. Average sensor lifespan is approximately 150,000 km. This issue does not affect the N46 engine.
Gasket hardens with age causing oil leaks onto exhaust manifold and ignition components · more· less
The valve cover gasket on both N46 and N43 engines hardens and shrinks over time, allowing oil to seep out. Oil can drip onto the exhaust manifold, creating a burning smell and smoke, or pool around the spark plug wells, contaminating the ignition coils and accelerating their failure. The gasket itself costs €30-60, but the job requires 2-3 hours of labor. Total cost at an independent shop is €200-400, while BMW dealers charge €400-600. On the N46, the valve cover also houses the crankcase ventilation (CCV) system. If the CCV diaphragm fails, the entire valve cover may need replacing at €200-400 for the part alone. This is a near-certainty on cars over 10 years old.
Expansion tank cracks, thermostat housing leaks, and water pump impeller can break · more· less
The E87 cooling system uses plastic components that become brittle with age and heat cycling. The expansion tank develops hairline cracks and can burst without warning, causing rapid coolant loss and overheating. The thermostat housing gasket becomes brittle and leaks. The mechanical water pump uses a plastic impeller that can erode or break. Individual repairs are relatively affordable (expansion tank €30-50, water pump €100-150), but a complete cooling system overhaul including thermostat, hoses, expansion tank, and water pump costs €400-700. Many experienced BMW owners replace the entire cooling system preventively. By 100,000 km, at least one component will have needed attention.
Variable valve timing solenoids clog or leak, causing rough idle and reduced power · more· less
Both the N46 and N43 engines use VANOS (variable valve timing) solenoids that can clog with oil sludge or develop external leaks through degraded O-ring seals. Symptoms include rough idle, poor acceleration, and VANOS-related fault codes. The O-ring seals harden over time and are a common source of minor oil leaks. Cleaning the solenoids and replacing O-rings costs €50-100. If the solenoids themselves have failed internally, replacement costs €150-300 per solenoid plus about 1 hour labor. In some cases the VANOS sprockets develop play and rattle, requiring more extensive work at €300-400.
Rear subframe rusts from stone chips and road salt, can fail inspection if severe · more· less
The E87 rear subframe is susceptible to corrosion on its lower edges where it is exposed to road spray, stone chips, and salt. This is well documented across the E87 community, with some owners reporting subframes corroded so severely they cracked, potentially damaging brake lines. Treatment involves wire-brushing surface rust and applying rust-inhibiting coatings (€300-500 professionally). If the subframe needs replacement, a used unit plus fitting costs €800-1,200. Finding a rust-free replacement is increasingly difficult. Cars from coastal areas or regions with heavy road salt are most affected. Preventive underbody wax treatment every two years significantly slows progression.
Water enters boot through rear light seals and vent panels, corroding the PDC module and causing cascading electrical faults · more· less
The E87 boot area is prone to water ingress through the rectangular vent panels behind the trim and through poorly sealed rear light housings. Water accumulates and soaks the PDC (parking distance control) module housed in the right side of the boot. A waterlogged PDC module sends corrupted signals on the CAN bus network, causing cascading electrical faults including complete instrument cluster failure, random warning lights, and central locking issues. DIY resealing of vents and light housings costs €10-20. If the PDC module is corroded, replacement costs €150-300. If other CAN bus modules are affected, diagnosis and repair can reach €500.
Clutch judder and flywheel vibration typically appear between 100,000-150,000 km on manual cars · more· less
Manual-equipped 118i models develop clutch judder when moving off, especially from cold and on inclines. The dual mass flywheel develops excessive play, producing vibration felt through the pedal and drivetrain. Combined clutch and DMF replacement costs €700-1,200 at an independent specialist, with parts (flywheel approximately €250-350, clutch kit approximately €150-200) plus 4-5 hours labor. This is a standard wear item that typically needs attention between 100,000 and 150,000 km depending on driving style. Urban stop-start driving accelerates wear significantly.
Engine choice determines your ownership experience
The BMW 118i E87's reliability depends heavily on which engine is fitted. The N46 (2005-2007) uses port injection and Valvetronic variable valve lift, making it simpler in some ways but adding Valvetronic motor and eccentric shaft concerns. The N43 (2007-2011 in Western Europe) replaced Valvetronic with direct injection, introducing expensive piezo injectors and a NOx sensor. Both variants share timing chain concerns, oil leak tendencies, and E87-specific body issues including rear subframe corrosion and boot water ingress. With regular oil changes (every 10,000-15,000 km rather than BMW's extended interval), proactive cooling system maintenance, and attention to known weak points, both engines can deliver reliable service well beyond 200,000 km.
Recalls and Technical Service Bulletins
Takata airbag inflator (various production dates)
Critical - verify completed
Fuel pump relay (certain 2006-2008 models)
Verify completed
Timing chain testing campaign (N43 engines, 2007-2011)
Verify completed
Contact a BMW dealer with the VIN to verify all recalls and service campaigns have been completed. The Takata airbag recall is a critical safety issue affecting many E87 models. The N43 timing chain testing campaign only checks for existing stretch and does not preventively replace the chain.
Warranty Status
Factory warranty (2 years)
Expired on all E87 models
Rust perforation warranty (12 years)
Expired on all E87 models
All BMW 118i E87 models are well outside their original 2-year factory warranty and 12-year rust perforation warranty. Third-party warranty providers may offer coverage but typically exclude known problem areas like timing chains and Valvetronic components.
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.