2010 BMW 135i

The 2010 BMW 135i is a popular compact performance car known for its engaging driving dynamics and potent engine. The standard engine is the N54 3.0-liter twin-turbocharged inline-six, producing 300 horsepower and 300 lb-ft of torque. Transmission options include a 6-speed manual and a 7-speed dual-clutch automatic (DCT). People often praise the 135i for its handling, quick acceleration, and relatively compact size, making it fun to drive on winding roads. Common complaints often revolve around reliability concerns, particularly issues related to the N54 engine’s high-pressure fuel pump and turbocharger system. Owners also report occasional electrical glitches and higher-than-average maintenance costs.

Engine

N54 3.0L Twin-Turbocharged Inline-Six

• High-Pressure Fuel Pump (HPFP) Failure
  • Description/Symptoms: Long cranking times, rough idling, and a check engine light. The car may go into limp mode or stall.
  • Solution: Replace the faulty HPFP.
  • Estimated Cost to Fix: $800 - $1,200+
  • Recalls: None Found
• Turbocharger Wastegate Rattle
  • Description/Symptoms: Rattling noise from the rear of the engine, especially during cold starts or acceleration. This is due to worn wastegate bushings on the turbochargers.
  • Solution: Replace the turbochargers or rebuild them with upgraded wastegate bushings.
  • Estimated Cost to Fix: $2,500 - $4,000+ (turbo replacement), $800-$1500 (rebuild with upgraded bushings, if possible)
  • Recalls: None Found
• Oil Leaks (Valve Cover Gasket, Oil Filter Housing Gasket)
  • Description/Symptoms: Visible oil leaks, burning oil smell, and low oil levels.
  • Solution: Replace the leaking gaskets.
  • Estimated Cost to Fix: Valve Cover Gasket: $400 - $700, Oil Filter Housing Gasket: $300 - $500
  • Recalls: None Found
• Fuel Injector Failure
  • Description/Symptoms: Rough idling, misfires, and a check engine light. May also experience fuel smell.
  • Solution: Replace faulty fuel injectors.
  • Estimated Cost to Fix: $250 - $400 per injector
  • Recalls: None Found

Transmission

6-Speed Manual

• Clutch Failure
  • Description/Symptoms: Clutch slippage, difficulty shifting, and a burning smell.
  • Solution: Replace the clutch disc, pressure plate, and potentially the flywheel.
  • Estimated Cost to Fix: $1,200 - $2,000+
  • Recalls: None Found

7-Speed Dual-Clutch Transmission (DCT)

• Mechatronic Unit Failure
  • Description/Symptoms: Rough shifting, delayed engagement, and transmission malfunction warnings.
  • Solution: Replace or repair the mechatronic unit.
  • Estimated Cost to Fix: $2,500 - $4,000+
  • Recalls: None Found

Suspension

• Control Arm Bushing Failure
  • Description/Symptoms: Clunking noises from the front suspension, especially over bumps. Vehicle may feel loose or wander at higher speeds.
  • Solution: Replace the worn control arm bushings.
  • Estimated Cost to Fix: $400 - $800
  • Recalls: None Found

Electrical

• Battery Drain
  • Description/Symptoms: The car’s battery drains quickly, especially when parked for extended periods.
  • Solution: Diagnose and repair the source of the parasitic drain. This could involve faulty sensors, modules, or wiring.
  • Estimated Cost to Fix: $100 - $500+ (depending on the source)
  • Recalls: None Found
• Faulty Window Regulators
  • Description/Symptoms: Windows not operating properly, making grinding noises, or falling into the door.
  • Solution: Replace the faulty window regulator.
  • Estimated Cost to Fix: $300 - $500
  • Recalls: None Found

Exterior

• Water Pump Failure
  • Description/Symptoms: Overheating, loss of coolant.
  • Solution: Replace the water pump.
  • Estimated Cost to Fix: $800 - $1200
  • Recalls: None Found

Interior

• No Issues Found

Summary

The 2010 BMW 135i is a fun and sporty car with a few common issues. The most significant concerns revolve around the N54 engine, particularly the HPFP, turbochargers, and oil leaks. These issues can be expensive to repair, potentially costing several thousand dollars. Electrical problems like battery drain can also be a nuisance. While the car offers a thrilling driving experience, potential buyers should be aware of these potential pitfalls and factor in higher-than-average maintenance costs.