BMW 118i F20

The N13 engine shares its timing chain design with several BMW engines known for premature wear. The chain stretches over time while the tensioner loses its ability to maintain pressure, particularly overnight. This produces a distinctive rattle on cold start lasting a few seconds to half a minute. Typically appears between 80,000 and 150,000 km, though some cars make it further with diligent oil changes. If the chain skips a tooth, it can cause piston-to-valve contact and catastrophic engine damage. Replacement at an independent specialist costs around €1,000-1,500 (chain, guides, tensioner, sprockets). If engine damage has already occurred, costs can escalate to €2,500 or more. BMW improved the tensioner design in later N13 production runs. The B38 LCI engine does not share this issue to the same degree.

The N13's turbocharger has two common weak points. First, the wastegate linkage develops play over time, producing a metallic rattle particularly at idle and low revs. A flapper repair kit costs around €50-80 and can be fitted without removing the turbo. Second, the diverter valve uses a rubber membrane that tears with age and heat cycling, causing boost leaks and loss of power. The membrane alone is inexpensive (€30-50) but access can add labor costs. If the entire turbo needs replacement due to internal damage from ingested debris (cracked intake hose pieces), costs rise to €1,200-1,500 at an independent specialist. Typically develops between 60,000 and 100,000 km.

Both the N13 and B38 use an integrated PCV (positive crankcase ventilation) system in the valve cover. The internal membrane cracks over time, causing increased oil consumption, rough idle, and potential misfires. Additionally, the valve cover gasket itself degrades, leading to external oil leaks visible around the top of the engine. BMW often recommends replacing the entire valve cover assembly rather than just the membrane, though aftermarket repair kits exist for the PCV alone. Parts cost €100-250 for an aftermarket cover or repair kit, with labor adding €150-300. Typically appears between 60,000 and 120,000 km.

A widespread issue across the entire F20 range regardless of engine. The electric power steering rack develops excessive play between its internal gear components and the EPS motor, causing a metallic clunking noise when driving over uneven surfaces. Some cars were covered under a BMW Quality Enhancement programme, though this was not widely publicized. DIY adjustment of the rack's preload bolt can sometimes eliminate the noise for minimal cost. If a new steering rack is required, expect €1,500-2,200 fitted at an independent specialist, or up to €2,700 at a BMW dealer. Typically develops between 40,000 and 80,000 km. Check whether the Quality Enhancement repair has been performed.

Both the N13 and B38 use an electric water pump and a plastic thermostat housing that degrades with heat cycling. The thermostat housing is known to crack and leak coolant. The water pump can fail electrically or develop bearing noise. Symptoms include coolant warning light, engine overheating, or poor cabin heating in winter. Specialists recommend replacing both components together since they share the same cooling circuit and have similar lifespans. Parts cost approximately €200-350, with labor around €200-450 depending on accessibility. Common between 80,000 and 130,000 km.

The N13 engine's high-pressure fuel pump can fail, typically between 60,000 and 100,000 km. Symptoms include difficult starting, engine stalling, and loss of power under acceleration. The fault code 11A002 (high pressure fuel plausibility) is commonly associated with this issue. A replacement pump costs €350-600 for the part, with labor around €150-400 depending on the workshop. Using quality fuel and maintaining regular service intervals helps extend pump life. This issue is specific to the N13 and does not affect the B38 LCI models.

The VANOS variable valve timing solenoids on both the N13 and B38 can become clogged with oil sludge or fail electrically. Symptoms include rough idle, reduced power particularly at low revs, poor fuel economy, and extended cranking on cold starts. The solenoids are relatively accessible and affordable to replace: parts cost approximately €80-150 per solenoid (two are used), with around one hour of labor. Regular oil changes with quality oil significantly reduce the likelihood of this issue. Most commonly appears between 60,000 and 100,000 km.

Electric window regulators on the F20 are a known weak point, particularly on the driver's side due to higher usage. The mechanism can fail (window drops into door panel or moves slowly) or the motor burns out (no response when pressing the switch). A replacement regulator costs €80-150 for the part, with about one hour of labor. Some owners report this happening as early as 60,000 km, though 80,000-120,000 km is more typical.