2003 INFINITI Q45

The 2003 INFINITI Q45 is a luxury sedan known for its powerful engine, comfortable ride, and upscale features. The Q45 came equipped with a 4.5-liter V8 engine (VK45DE) producing 340 horsepower and 333 lb-ft of torque, paired with a 5-speed automatic transmission. Many owners appreciate the Q45’s smooth acceleration, spacious interior, and advanced technology for its time. However, some common complaints include the car’s complex electronic systems leading to potential issues, the car’s uninspiring exterior design (specifically when compared to earlier generations of the car), and relatively poor fuel economy compared to some competitors.

Engine

4.5L V8 (VK45DE)

• Excessive Oil Consumption
  • Description/Symptoms: Some owners have reported excessive oil consumption, requiring them to add oil between scheduled oil changes. The cause can be worn valve stem seals or piston rings. Symptoms include the need to frequently top off oil levels, blue smoke from the exhaust, and a burning oil smell.
  • Solution: The repair may require replacing the valve stem seals or piston rings, which involves disassembling the engine. A compression test and leak-down test can help diagnose the problem.
  • Estimated Cost to Fix: $1,500 - $4,000+
  • Recalls: None Found
• Timing Chain Tensioner Failure
  • Description/Symptoms: The hydraulic timing chain tensioner can fail, leading to a rattling noise from the engine, especially at startup. If left unattended, this can cause significant engine damage due to timing chain slack.
  • Solution: Replace the timing chain tensioner. It is often recommended to replace the timing chain and guides at the same time.
  • Estimated Cost to Fix: $800 - $1,500+
  • Recalls: None Found

Transmission

5-Speed Automatic

• Transmission Slipping or Harsh Shifting
  • Description/Symptoms: Some owners have reported transmission slipping, particularly between gears, or experiencing harsh shifts. This can be due to worn clutch packs, valve body issues, or low transmission fluid levels.
  • Solution: Check and replace the transmission fluid. If the issue persists, the valve body may need to be rebuilt or replaced, or the transmission may need a complete overhaul.
  • Estimated Cost to Fix: $200 (fluid change) - $3,000+ (overhaul)
  • Recalls: None Found

Suspension

• Air Suspension Failure
  • Description/Symptoms: The Q45’s air suspension system can be prone to failure, leading to the car sagging on one or more corners, a rough ride, and an illuminated warning light on the dashboard. The air struts, compressor, or air lines can all fail.
  • Solution: Replace the faulty air struts, compressor, or air lines. Many owners opt to convert to a coil-over suspension system for increased reliability.
  • Estimated Cost to Fix: $500 - $1,500+ per air strut, $400 - $800+ for the compressor. Conversion to coil-overs $1,000 - $2,500+
  • Recalls: None Found

Electrical

• Instrument Cluster Issues
  • Description/Symptoms: Some owners have reported issues with the instrument cluster, including dim or non-functional displays, inaccurate readings, or complete failure.
  • Solution: Repair or replace the instrument cluster.
  • Estimated Cost to Fix: $300 - $800+
  • Recalls: None Found
• BCM (Body Control Module) Issues
  • Description/Symptoms: Problems with the BCM can cause a wide range of electrical issues, including malfunctioning power windows, door locks, lighting, and other accessories.
  • Solution: Diagnose and replace or reprogram the BCM.
  • Estimated Cost to Fix: $400 - $1,200+
  • Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: The sunroof can experience issues such as failing to open or close properly, leaking, or making excessive noise. The motor, tracks, or seals can be the cause.
  • Solution: Repair or replace the sunroof motor, tracks, or seals.
  • Estimated Cost to Fix: $200 - $800+
  • Recalls: None Found

Interior

• Navigation System Failure
  • Description/Symptoms: The navigation system, being an early version of the technology, can be prone to failure or malfunction. This includes issues with the display screen, GPS reception, or software errors.
  • Solution: Repair or replace the navigation system unit, or update the software if possible. Due to the age of the system, replacement options may be limited.
  • Estimated Cost to Fix: $300 - $1,000+ (replacement may be difficult)
  • Recalls: None Found
• Climate Control Issues
  • Description/Symptoms: Problems with the climate control system, such as the AC not blowing cold air, the heater not working, or issues with the blend doors directing air flow.
  • Solution: Diagnose and repair the AC compressor, heater core, or blend door actuators.
  • Estimated Cost to Fix: $200 - $1,000+
  • Recalls: None Found

Summary:

The 2003 INFINITI Q45 offers a luxurious driving experience, but potential buyers should be aware of the common issues that can arise with age. Engine oil consumption, timing chain tensioner issues, air suspension failures, and electrical problems are among the most prevalent. Repair costs can range from a few hundred dollars for minor fixes to several thousand dollars for major engine or suspension overhauls. Due to the complexity of the vehicle’s systems, proper diagnosis by a qualified mechanic is essential. The severity of these issues can vary depending on the vehicle’s maintenance history and overall condition.