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2008 BMW 335i

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By Research the Car 4 min read

The 2008 BMW 335i is a popular luxury sports sedan known for its engaging driving dynamics and powerful performance. The main engine option for the 2008 335i is the N54 3.0-liter twin-turbocharged inline-six, producing 300 horsepower and 300 lb-ft of torque. It was available with either a 6-speed manual or a 6-speed automatic transmission. People generally appreciate the 335i’s responsive engine, sharp handling, and upscale interior. Common complaints include its complex and sometimes unreliable engine, expensive maintenance, and occasional electrical gremlins.

Engine

N54 3.0L Twin-Turbo Inline-Six

  • High Pressure Fuel Pump (HPFP) Failure
    • Description/Symptoms: Long cranking times, extended cranking, rough idling, and sudden loss of power or stalling. A fuel pump malfunction light or engine malfunction light may illuminate on the dash.
    • Solution: Replace the High Pressure Fuel Pump.
    • Estimated Cost to Fix: $600 - $1200+
    • Recalls: None Found
  • Turbocharger Wastegate Rattle
    • Description/Symptoms: A rattling or buzzing sound coming from the engine bay, especially during cold starts or when the engine is under light load. This is caused by excessive play in the turbocharger wastegate actuator arms.
    • Solution: Replace the turbochargers or install aftermarket wastegate actuator arms or clips to reduce the play.
    • Estimated Cost to Fix: $2500 - $4000+ (turbo replacement), $200 - $500+ (wastegate actuator repair)
    • Recalls: None Found
  • Fuel Injector Failure
    • Description/Symptoms: Rough idle, misfires, poor fuel economy, and a noticeable loss of power. Can trigger a check engine light.
    • Solution: Replace faulty fuel injectors. It’s often recommended to replace all injectors at the same time for balanced performance.
    • Estimated Cost to Fix: $200 - $400+ per injector, $1200 - $2400+ for a complete set
    • Recalls: None Found
  • Oil Leaks (Valve Cover Gasket, Oil Filter Housing Gasket)
    • Description/Symptoms: Visible oil leaks on the engine, burning oil smell, and low oil level.
    • Solution: Replace the valve cover gasket and/or oil filter housing gasket.
    • Estimated Cost to Fix: $300 - $600 (valve cover gasket), $200 - $400 (oil filter housing gasket)
    • Recalls: None Found
  • Carbon Buildup on Intake Valves
    • Description/Symptoms: Rough idle, reduced power, poor throttle response, and misfires. Common due to the direct injection design.
    • Solution: Walnut blasting to remove carbon deposits from the intake valves.
    • Estimated Cost to Fix: $400 - $800+
    • Recalls: None Found

Transmission

6-Speed Automatic (GM 6L45R)

  • Mechatronic Sleeve Leaks
    • Description/Symptoms: Transmission fluid leaks, rough shifting, slipping gears, or failure to shift.
    • Solution: Replace the mechatronic sleeve and change the transmission fluid.
    • Estimated Cost to Fix: $300 - $600+
    • Recalls: None Found
  • Valve Body Issues
    • Description/Symptoms: Harsh or erratic shifting, slipping between gears, delayed engagement, or failure to shift at all.
    • Solution: Replacement or repair of the valve body.
    • Estimated Cost to Fix: $800 - $2000+
    • Recalls: None Found

Suspension

  • Control Arm Bushing Failure
    • Description/Symptoms: Clunking noises from the front suspension, particularly when going over bumps, loose steering feel, and uneven tire wear.
    • Solution: Replace the control arm bushings or the entire control arm assembly.
    • Estimated Cost to Fix: $200 - $500+ per control arm
    • Recalls: None Found
  • Strut/Shock Absorber Failure
    • Description/Symptoms: Bouncy ride, poor handling, excessive body roll, and fluid leaks from the struts/shocks.
    • Solution: Replace the struts/shocks.
    • Estimated Cost to Fix: $400 - $1000+ per axle
    • Recalls: None Found

Electrical

  • Battery Drain
    • Description/Symptoms: Dead battery, difficulty starting the car, and electrical systems malfunctioning. Can be caused by a variety of issues, including faulty modules, aftermarket accessories, or a failing battery.
    • Solution: Diagnose and repair the source of the battery drain. This may involve replacing the battery, fixing wiring issues, or replacing faulty modules.
    • Estimated Cost to Fix: $100 - $500+ (depending on the cause)
    • Recalls: None Found
  • FRM (Footwell Module) Failure
    • Description/Symptoms: Loss of control over lights, windows, locks, and other electrical functions.
    • Solution: Reprogram or replace the FRM module.
    • Estimated Cost to Fix: $300 - $800+
    • Recalls: None Found

Exterior

  • Water Pump Failure
    • Description/Symptoms: Overheating engine, coolant leaks, and warning lights on the dashboard.
    • Solution: Replace the water pump and thermostat.
    • Estimated Cost to Fix: $600 - $1200+
    • Recalls: None Found

Interior

  • Sticking Door Locks
    • Description/Symptoms: Door locks failing to lock/unlock, usually caused by worn lock actuators.
    • Solution: Replace faulty door lock actuators.
    • Estimated Cost to Fix: $200-$500 per door.
    • Recalls: None Found

Summary

The 2008 BMW 335i is a performance-oriented vehicle that offers a thrilling driving experience. However, it is prone to several common issues, particularly related to the N54 engine, including HPFP failure, turbocharger wastegate rattle, and carbon buildup. Transmission issues with the automatic are also common. Suspension and electrical problems are also present but less common. Repair costs can be significant, making thorough inspection and maintenance essential for owners. While some issues are relatively minor, others can be quite expensive, requiring careful consideration when purchasing or maintaining this model.

BMW, 335i
BMW 335i 2008
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