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2008 BMW 120i

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By Research the Car 6 min read

The 2008 BMW 120i is a compact hatchback that offers a blend of sporty handling and everyday practicality. While its relatively small size makes it maneuverable in urban environments, some find the rear seats and cargo area a bit cramped. Other engine options available include the 1.6L N43B16 (85 kW / 115 hp), 2.0L N46B20 (95-125 kW / 129-170 hp), and the 2.0L N43B20 (105-125 kW / 143-170 hp) gasoline engines, and the 2.0L M47D20 (90-120 kW / 122-163 hp) and the 2.0L N47D20 (105-130 kW / 143-177 hp) diesel engines. The 2.0L N46B20 engine that produces 115 kW (156 hp) and 200 Nm (147 lb-ft) of torque is a common option. Transmission options include a 6-speed manual and a 6-speed automatic. Owners often praise the 120i for its engaging driving dynamics and relatively fuel-efficient engine options. However, common complaints include electrical issues and higher than average maintenance costs.

Engine

2.0L N46B20 (Petrol)

  • Oil Leaks
    • Description/Symptoms: Oil leaks are frequently reported around the valve cover gasket, oil filter housing gasket, and oil pan gasket. This can result in visible oil spots on the ground and a burning oil smell.
    • Solution: Replace the leaking gasket. Ensure proper torque when reinstalling components.
    • Estimated Cost to Fix: $150 - $500+ depending on the location and labor.
    • Recalls: None Found
  • VANOS Solenoid Failure
    • Description/Symptoms: Rough idling, decreased engine performance, and potential stalling. Diagnostic trouble codes (DTCs) related to VANOS system errors (e.g., P0011, P0012, P0014, P0015) will be present.
    • Solution: Replace the faulty VANOS solenoid(s). Cleaning the solenoid might offer a temporary fix.
    • Estimated Cost to Fix: $200 - $400+
    • Recalls: None Found
  • Coolant Leaks
    • Description/Symptoms: Loss of coolant, overheating, and the need to frequently top off the coolant reservoir. Common leak locations include the water pump, thermostat housing, and radiator hoses.
    • Solution: Identify and replace the leaking component.
    • Estimated Cost to Fix: $100 - $600+
    • Recalls: None Found

2.0L N43B20 (Petrol)

  • Direct Injection Issues
    • Description/Symptoms: Carbon buildup on intake valves due to direct injection. This can lead to rough idling, misfires, and reduced engine performance.
    • Solution: Perform intake valve cleaning (e.g., walnut blasting) to remove carbon deposits.
    • Estimated Cost to Fix: $400 - $800+
    • Recalls: None Found
  • High Pressure Fuel Pump (HPFP) Failure
    • Description/Symptoms: Long cranking times, difficulty starting, and potential stalling. Diagnostic trouble codes related to fuel pressure issues may be present.
    • Solution: Replace the faulty HPFP.
    • Estimated Cost to Fix: $600 - $1200+
    • Recalls: None Found

2.0L M47D20 & N47D20 (Diesel)

  • Timing Chain Issues (N47D20)
    • Description/Symptoms: Rattling noise from the rear of the engine, especially on startup and idle. If left unaddressed, the timing chain can break, causing catastrophic engine damage. This is especially prevalent in earlier N47D20 engines.
    • Solution: Replace the timing chain, sprockets, and tensioners.
    • Estimated Cost to Fix: $1500 - $3000+ due to the location of the timing chain at the rear of the engine.
    • Recalls: None Found
  • Swirl Flap Issues (M47D20)
    • Description/Symptoms: Swirl flaps breaking and going into the engine, rough idling, and reduced engine performance
    • Solution: Remove the swirl flaps and install the blanking plates
    • Estimated Cost to Fix: $500-$1,000+
    • Recalls: None Found

Transmission

6-Speed Automatic (All Engine Options)

  • Slipping or Harsh Shifting
    • Description/Symptoms: The transmission may slip between gears, shift harshly, or hesitate when shifting. This can be caused by worn friction plates, a faulty valve body, or low transmission fluid.
    • Solution: Perform a transmission fluid flush and filter replacement. If the problem persists, the valve body may need to be rebuilt or replaced, or the entire transmission may need to be rebuilt or replaced.
    • Estimated Cost to Fix: $200 (fluid flush) to $3000+ (rebuild/replacement)
    • Recalls: None Found

Suspension

  • Worn Control Arm Bushings
    • Description/Symptoms: Clunking noises from the front suspension, especially over bumps. Vehicle may exhibit vague steering and poor handling.
    • Solution: Replace the worn control arm bushings or the entire control arm assembly.
    • Estimated Cost to Fix: $200 - $500+ per side
    • Recalls: None Found
  • Broken Coil Springs
    • Description/Symptoms: Sagging suspension, uneven tire wear, and a clunking noise. Visually inspect the coil springs for cracks or breaks.
    • Solution: Replace the broken coil spring(s). It is recommended to replace coil springs in pairs.
    • Estimated Cost to Fix: $300 - $600+ per pair
    • Recalls: None Found

Electrical

  • Faulty Window Regulator
    • Description/Symptoms: Window may not go up or down, or may move erratically. A clicking sound may be heard from the door panel when the window switch is activated.
    • Solution: Replace the faulty window regulator.
    • Estimated Cost to Fix: $200 - $400+
    • Recalls: None Found
  • Battery Drain Issues
    • Description/Symptoms: The battery drains quickly, especially when the car is parked for extended periods. This can be caused by a faulty module that is not shutting down properly, or a parasitic draw from an aftermarket accessory.
    • Solution: Diagnose and repair the source of the parasitic draw. This may involve replacing a faulty module or disconnecting an aftermarket accessory.
    • Estimated Cost to Fix: $100 - $500+ (depending on the complexity of the issue)
    • Recalls: None Found

Exterior

  • Rust on Tailgate/Hatch
    • Description/Symptoms: Surface rust, bubbling paint, or even holes forming along the lower edge of the tailgate/hatch. This is a common issue, especially in areas with road salt.
    • Solution: Remove rust, repair any damage, and repaint the affected area. In severe cases, the entire tailgate/hatch may need to be replaced.
    • Estimated Cost to Fix: $200 - $1000+ depending on the severity.
    • Recalls: None Found

Interior

  • Sticking Door Lock Actuators
    • Description/Symptoms: Doors may not lock or unlock properly using the key fob or interior switches. The door lock actuator may make a clicking sound but fail to engage.
    • Solution: Replace the faulty door lock actuator.
    • Estimated Cost to Fix: $200 - $400+ per door
    • Recalls: None Found
  • Headliner Sagging
    • Description/Symptoms: The headliner fabric begins to detach from the backing board, especially in areas exposed to heat.
    • Solution: Replace the headliner fabric or the entire headliner assembly.
    • Estimated Cost to Fix: $300 - $700+
    • Recalls: None Found

Summary

The 2008 BMW 120i, while enjoyable to drive, has several potential issues that prospective buyers should be aware of. Engine issues, particularly oil leaks and VANOS problems in the N46B20 engine and timing chain issues in the N47D20 engine, are common and can be costly to repair. Transmission problems, suspension wear, and electrical faults also contribute to the potential for higher-than-average maintenance costs. The severity of these issues ranges from relatively minor (e.g., replacing a window regulator) to potentially catastrophic (e.g., engine damage from a broken timing chain). Overall, due diligence and a thorough pre-purchase inspection are crucial to avoid unexpected expenses.

BMW, 120i
BMW 120i 2008
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