BMW 118i F20 Reliability

This is the most serious issue with pre-2015 118i models. The timing chain, guides, and tensioners on the N13 engine (co-developed with Peugeot) were poorly designed. Owners commonly report a distinctive rattling noise during cold start that lasts 1-30 seconds. This typically occurs between 60,000-120,000 km. Because this is an interference engine, chain failure can cause catastrophic valve and piston damage. Parts cost approximately €400-700, with labor adding €500-1,500 depending on the shop. BMW never officially acknowledged this problem in the EU and did not issue a recall. One workshop reported they perform one N13 timing chain replacement per week. If you hear cold start rattle lasting more than a few seconds, walk away or budget for immediate replacement. The B38 engine (2015+) does not have this issue.

This is an extremely common problem affecting thousands of N13-equipped F20 owners worldwide. Many owners report consuming 1 liter of oil every 1,000-1,800 km, requiring frequent top-ups between services. The most common cause is deteriorated valve stem seals, which harden and crack due to heat cycles. Oil seeps past the valve guides into the combustion chamber and burns. There's typically no blue smoke, no diagnostic codes, and no power loss - making it easy to overlook until serious damage occurs. Oil consumption and timing chain wear are separate issues on the N13 - one owner reported their oil warning light came on every 1,000 miles until the timing chain was replaced at 66,000 miles, after which "it hasn't used a drop since". Valve stem seal replacement costs approximately €1,500-1,700 at independent shops. Issues typically manifest between 60,000-120,000 km. Check service records carefully for oil top-ups. The B38 engine (2015+) largely avoids this problem.

The turbocharger is a common failure point on N13-equipped 118i models, with problems typically arising between 60,000-100,000 km. One workshop reported handling 4 vehicles with turbo problems at the same mileage range (80,000-110,000 km) in a single week. Turbo Direct specialists stated they perform about 10 turbo replacements per month for this model. Common symptoms include loss of power, excessive smoke, and unusual whining or whistling sounds. The turbo actuator tends to stick if the car is driven too gently or only for short trips, as carbon builds up. This causes the EPC warning light and limp mode. VW/BMW won't sell the actuator separately. Actuator-only repair at a specialist costs €500-600, but if turbo internals are damaged, full replacement runs €1,200-2,500. Some forum users claim "I have not heard of a single person with a 116i/118i who hasn't had problems with the cooling system and/or turbo at stupidly low mileage." Using premium fuel and regular spirited driving helps prevent actuator sticking. B38 engines (2015+) have improved reliability.

The F20 118i often faces stalling during cold starts and prolonged cranking times in low temperatures. Code 11A002 indicates a high-pressure fuel pump plausibility fault, often triggered by cold weather affecting fuel delivery. The HPFP boosts fuel pressure to extremely high levels (often exceeding 1,000 PSI) required for direct injection systems. One 2015 118i owner reported that "when cold and you first start it, car can cut out sometimes. Logged HPFP and it drops off when it runs rough." Parts cost for an OEM Bosch HPFP is approximately €190-400, with labor adding €500-800 (typically 3-6 hours). HPFP replacements almost always require replacing the fuel filter simultaneously, adding €50-200. You'll usually pay a diagnostic fee (€100-200) to confirm the HPFP is the issue. Independent shops charge €80-150/hour, while BMW dealerships command €150-250+/hour. This is a well-documented weak point on the N13 engine.

The F20 118i uses an electric water pump with a typical service life of approximately 60,000 miles (96,000 km). Many owners report overheating warnings appearing when the car reaches operating temperature. The expansion tank is also a common failure point on cars of this age, with replacement parts costing around €200-300. Some owners have experienced water pump failures at relatively low mileage - around 60,000 km. Parts costs include: water pump €285-500 (genuine BMW €500+), thermostat €54-110, U-shaped hose connecting pump and thermostat €20-50, OE BMW coolant €22.50 per bottle. Total parts cost approximately €360-380. A professional installation at a dealer or independent shop will cost €700-1,200 total. Thanks to the electric water pump design, a DIY job can be completed in 1-2 hours with the right tools. Symptoms include overheating, coolant warning light, and poor cabin heating. The cooling fans may also fail to kick in properly when the engine is at operating temperature. This affects all F20 years (both N13 and B38 engines).

The VANOS system adjusts valve timing to enhance performance and fuel efficiency. The solenoids controlling this system can become clogged with oil sludge or fail electrically, leading to reduced power output, lack of power during acceleration, and decreased fuel efficiency. Symptoms are often subtle - you may notice the car feels less responsive or fuel economy has gradually worsened. There are two VANOS solenoids (intake and exhaust), each costing approximately €100 for OEM parts (Febi or Pierburg brands recommended). Labor is minimal for DIY mechanics - about 20 minutes per solenoid if you're comfortable. Professional installation costs €200-400 for labor. Some owners report repairs costing €250-300 when including oil buildup cleaning. Complete VANOS unit replacement (if more extensive damage exists) can cost €1,200-2,500, though this is rare. The issue affects both N13 and B38 engines but is more common on higher mileage N13 units. Regular oil changes with high-quality oil help prevent solenoid clogging.

Ignition coil failures occur frequently across the F20 range due to excessive heat exposure, electrical faults, and moisture infiltration. Oil leaks from valve cover gaskets and other engine seals can contaminate the ignition coils, accelerating failure. Symptoms include engine misfiring, rough running (especially at idle), reduced fuel economy, poor acceleration response, check engine light, hard starting or no-start conditions, and in extreme cases, engine stalling. BMW ignition coils can last upward of 140,000 km under ideal conditions, but oil contamination dramatically reduces lifespan. Parts cost €40-80 per coil (4 cylinders on N13 = €160-320 total, 3 cylinders on B38 = €120-240 total). Labor at independent shops costs approximately €75-100, while dealers charge €200-300. One coil replacement typically costs €145-226. If all coils need replacing, dealer costs can reach €700. Coils should always be replaced in sets if multiple have failed. The most common cause of premature failure is overvoltage from faulty spark plugs or plug wires - maintain proper service intervals to avoid higher costs. Failed coils can allow unburned fuel to enter and permanently damage the catalytic converter from overheating (€1,000+ repair).

Electrical problems are among the most frequently reported issues by F20 owners. Many report that if the car isn't driven for about 4 days, they get the "Battery draining when stationary" message and sometimes the car won't start. Testing with a multimeter shows parasitic drain - in one case, when the car goes into sleep mode, the drain measured 1.7 amps (should be 0.03-0.06 amps). Common causes include: aftermarket accessories drawing power (tow bars with generic relay systems, dashcams left powered), devices left plugged into cigarette lighter ports (phone chargers preventing the Front Electronic Module from shutting down, drawing 1 amp/hour), and the car failing to enter sleep mode properly (hazard and start-stop button lights remain on after 20 minutes). One owner found their issue was a phone charger left plugged in - once removed, problem solved. A new battery costs €230-300 including mobile fitting and registration/coding (required to prevent overcharging). Halfords quotes around €230, AA quotes €260-299. Strongly advised to detach all devices from cigarette lighter ports when parking. For extended periods without use, connect a battery maintainer. Diagnosing requires disconnecting the positive terminal and bridging with an ammeter to measure drain.