2005 BMW 120i

The 2005 BMW 120i is a compact hatchback known for its sporty handling and premium features. It was available with several engine options including the 1.6L N43B16, 2.0L N46B20, 2.0L N43B20, and the 2.0L N45B20 inline-4 petrol engines. The 2.0L N46B20, which is the focus for this response, produces approximately 110 kW (150 hp) and 200 Nm (147 lb-ft) of torque. Common transmissions included a 6-speed manual and a 6-speed automatic. Owners typically appreciate the car’s engaging driving experience and relatively fuel-efficient engines. On the other hand, the 120i is often criticized for its cramped rear seats, some reliability issues, and higher maintenance costs compared to other hatchbacks.

Engine

N46B20 (2.0L Inline-4 Petrol)

• Oil Leaks
  • Description/Symptoms: Oil leaks often develop from the valve cover gasket, oil filter housing gasket, or the oil pan gasket. Symptoms include visible oil drips under the car, a burning oil smell, and low oil levels.
  • Solution: Replacing the affected gasket(s). Thoroughly cleaning the affected areas.
  • Estimated Cost to Fix: $200 - $600+ depending on which gasket and labor rates.
  • Recalls: None Found
• VANOS Solenoid Failure
  • Description/Symptoms: The VANOS (Variable Valve Timing) system can experience issues with the solenoids that control oil flow to the VANOS units. Symptoms include rough idling, loss of power, poor fuel economy, and engine error codes related to VANOS.
  • Solution: Replacing the faulty VANOS solenoid(s).
  • Estimated Cost to Fix: $200 - $400+ per solenoid, including labor.
  • Recalls: None Found
• Timing Chain Issues
  • Description/Symptoms: The N46B20 engine can experience timing chain stretch or failure, leading to rattling noises from the engine, especially during cold starts. In severe cases, this can cause engine damage.
  • Solution: Replacing the timing chain, guides, and tensioner.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found

Transmission

6-Speed Automatic (Specific Manufacturer Unspecified)

• Rough Shifting/Slipping
  • Description/Symptoms: The automatic transmission may exhibit rough shifting, hesitation, or slipping between gears. This can be caused by low transmission fluid, worn clutches, or a failing valve body.
  • Solution: Check and top off transmission fluid (if applicable, some are “sealed for life”). Perform a transmission fluid and filter change. Replace the valve body or rebuild the transmission if the issue persists.
  • Estimated Cost to Fix: $100 (fluid change) - $3000+ (transmission rebuild/replacement).
  • Recalls: None Found
• Torque Converter Issues
  • Description/Symptoms: The torque converter may fail, leading to shuddering, stalling, or poor acceleration.
  • Solution: Replacing the torque converter.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found

Suspension

• Worn Suspension Components
  • Description/Symptoms: Common issues include worn control arm bushings, ball joints, and shock absorbers. Symptoms include clunking noises over bumps, poor handling, and uneven tire wear.
  • Solution: Replacing the worn suspension components.
  • Estimated Cost to Fix: $200 - $800+ per corner, depending on the components replaced and labor rates.
  • Recalls: None Found

Electrical

• Faulty Ignition Coils
  • Description/Symptoms: Misfires can occur due to faulty ignition coils. This results in rough running, loss of power, and the engine management light illuminating.
  • Solution: Replacing the faulty ignition coil(s).
  • Estimated Cost to Fix: $100 - $300+ per coil, including labor.
  • Recalls: None Found
• Battery Drain Issues
  • Description/Symptoms: The car’s battery may drain quickly, especially if it’s not driven frequently. This can be caused by a parasitic drain from a faulty module or accessory.
  • Solution: Diagnose the source of the parasitic drain and repair or replace the faulty component.
  • Estimated Cost to Fix: $100 - $500+, depending on the complexity of the issue.
  • Recalls: None Found

Exterior

• Rust
  • Description/Symptoms: Rust can develop in areas like the wheel arches, door bottoms, and around the trunk.
  • Solution: Repairing and repainting the affected areas.
  • Estimated Cost to Fix: $200 - $1000+ per panel, depending on the severity of the rust and the quality of the repair.
  • Recalls: None Found

Interior

• Window Regulator Failure
  • Description/Symptoms: The power windows may stop working due to a faulty window regulator.
  • Solution: Replacing the window regulator.
  • Estimated Cost to Fix: $200 - $400+ per window.
  • Recalls: None Found
• Faulty Door Lock Actuators
  • Description/Symptoms: The door locks may fail to lock or unlock properly.
  • Solution: Replacing the faulty door lock actuator.
  • Estimated Cost to Fix: $200 - $400+ per door.
  • Recalls: None Found

Summary

The 2005 BMW 120i with the N46B20 engine and automatic transmission faces several potential issues, primarily concerning the engine, transmission, suspension, and electrical systems. Engine issues like oil leaks, VANOS problems, and timing chain wear can lead to moderate to significant repair costs. Transmission problems, such as rough shifting, slipping, and torque converter failure, can also be expensive to address. Suspension and electrical issues, like worn components and battery drain, can contribute to the overall cost of ownership. While some issues may be minor, others can be severe and costly to repair, making a pre-purchase inspection crucial. Rust can be a concern for the body.