2005 BMW 645Ci

The 2005 BMW 645Ci is a grand touring coupe that was praised for its stylish design, comfortable ride, and powerful engine. It’s powered by a 4.4-liter V8 engine producing 325 horsepower and 330 lb-ft of torque. A 6-speed manual or a 6-speed automatic transmission were available. Owners often appreciate the car’s luxurious features, sporty handling, and distinctive appearance. Common dislikes include its complicated electronics, potential for costly repairs, and somewhat cramped rear seating. This guide covers common issues and complaints reported by owners of the 2005 BMW 645Ci.

Engine

4.4L N62 V8

• Valve Stem Seal Failure
  • Description/Symptoms: Excessive oil consumption, blue smoke from the exhaust upon start-up or after idling.
  • Solution: Replace the valve stem seals.
  • Estimated Cost to Fix: $3,000 - $6,000+
  • Recalls: None Found
• Coolant Leaks
  • Description/Symptoms: Coolant leaks from various locations including the water pump, coolant expansion tank, radiator hoses, and valley pan. Overheating can occur.
  • Solution: Replace the leaking components. Common culprits are the water pump, expansion tank, and valley pan gasket.
  • Estimated Cost to Fix: Water pump: $500 - $1,000; Expansion tank: $200 - $500; Valley pan gasket: $1,500 - $3,000.
  • Recalls: None Found
• Oil Leaks
  • Description/Symptoms: Oil leaks from valve cover gaskets, oil pan gasket, and the rear main seal. Burning oil smell can be present.
  • Solution: Replace the leaking gaskets and seals.
  • Estimated Cost to Fix: Valve cover gaskets: $500 - $1,000; Oil pan gasket: $800 - $1,500; Rear main seal: $1,000 - $2,000+
  • Recalls: None Found

Transmission

6-Speed Automatic (ZF 6HP26)

• Slipping and Harsh Shifting
  • Description/Symptoms: Hesitation between gear changes, rough or jerky shifts, transmission slipping. This is often related to low fluid level or worn valve body components.
  • Solution: Perform a transmission service including fluid and filter change. If the problem persists, the valve body may need to be rebuilt or replaced.
  • Estimated Cost to Fix: Transmission service: $300 - $600; Valve body replacement: $1,500 - $3,000+
  • Recalls: None Found
• Mechatronic Sleeve Leak
  • Description/Symptoms: Transmission fluid leak around the transmission pan. Can cause shift issues if fluid level gets too low.
  • Solution: Replace the mechatronic sleeve and fluid.
  • Estimated Cost to Fix: $500 - $1,000
  • Recalls: None Found

6-Speed Manual

No Issues Found

Suspension

• Control Arm Bushing Failure
  • Description/Symptoms: Clunking noises from the front suspension, vague steering, uneven tire wear.
  • Solution: Replace the worn control arm bushings or the entire control arm.
  • Estimated Cost to Fix: Bushing replacement: $300 - $600 per arm; Control arm replacement: $500 - $1,000 per arm.
  • Recalls: None Found
• Active Roll Stabilization (ARS) Issues
  • Description/Symptoms: Warning lights on the dashboard, reduced handling performance, clunking noises from the suspension.
  • Solution: Diagnose the ARS system and replace any faulty components, such as the hydraulic pump, valve block, or sensors.
  • Estimated Cost to Fix: Varies greatly depending on the component. $500 - $2,000+
  • Recalls: None Found

Electrical

• Battery Drain
  • Description/Symptoms: Dead battery after short periods of inactivity, difficulty starting the car. Can be caused by a faulty voltage regulator, parasitic draw from aftermarket accessories or failing modules.
  • Solution: Diagnose the cause of the battery drain and repair or replace the faulty component.
  • Estimated Cost to Fix: Varies depending on the component causing the drain. $100 - $1,000+
  • Recalls: None Found
• iDrive System Malfunctions
  • Description/Symptoms: iDrive screen freezing, system resets, inability to control functions, error messages.
  • Solution: Software update, replacement of the iDrive controller or the entire iDrive module.
  • Estimated Cost to Fix: Software update: $100 - $300; Controller replacement: $500 - $1,000; Module replacement: $1,000 - $2,500+
  • Recalls: None Found
• ABS/DSC Module Failure
  • Description/Symptoms: ABS and DSC warning lights on the dashboard, loss of ABS and stability control functionality.
  • Solution: Replacement of the ABS/DSC module. May require coding to the vehicle.
  • Estimated Cost to Fix: $800 - $1,500+
  • Recalls: None Found

Exterior

• Convertible Top Malfunctions (Convertible Models Only)
  • Description/Symptoms: Top not opening or closing properly, hydraulic leaks, error messages.
  • Solution: Diagnose the cause of the malfunction and repair or replace the faulty components, such as the hydraulic pump, cylinders, or sensors.
  • Estimated Cost to Fix: Varies depending on the component. $500 - $3,000+
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof not opening or closing properly, binding, motor failure.
  • Solution: Diagnose and repair or replace the sunroof motor, tracks, or associated components.
  • Estimated Cost to Fix: $300 - $1,000+
  • Recalls: None Found
• Seat Motor Failure
  • Description/Symptoms: Seats not adjusting properly, clicking noises from the seat motors.
  • Solution: Replace the faulty seat motors or repair the wiring.
  • Estimated Cost to Fix: $300 - $800 per seat
  • Recalls: None Found

Summary

The 2005 BMW 645Ci, while a stylish and enjoyable car, has several potential problem areas. Engine issues, particularly oil and coolant leaks, and valve stem seals, can be costly to address. Transmission problems, especially with the automatic, are also common. Electrical gremlins within the iDrive system and other modules can be frustrating. Suspension issues can impact ride quality and handling. Overall, potential owners should be aware of these common problems and budget accordingly for potential repairs. The severity of the issues range from minor electrical problems to major engine overhauls, with repair costs ranging from a few hundred to several thousand dollars. A thorough pre-purchase inspection by a qualified mechanic is highly recommended.