2004 INFINITI QX56
The 2004 INFINITI QX56 marked INFINITI’s entry into the full-size SUV market. It came equipped with a single engine option: a 5.6L VK56DE V8 engine producing 315 horsepower and 390 lb-ft of torque. This engine was paired with a 5-speed automatic transmission. Owners generally appreciated the QX56 for its spacious interior, powerful engine, and towing capacity. However, some common complaints included its large size making it difficult to maneuver in tight spaces, relatively poor fuel economy, and some reliability concerns.
Engine
5.6L VK56DE V8
- Timing Chain Tensioner Failure
- Description/Symptoms: Rattling noise upon startup, especially when cold. This is due to the timing chain tensioners losing pressure, causing the timing chain to slap against the guides. In severe cases, this can lead to engine misfires or even engine damage.
- Solution: Replace the timing chain tensioners, guides, and timing chain. It’s also advisable to inspect the oil pump for wear.
- Estimated Cost to Fix: $1500 - $3000+
- Recalls: None Found
- Exhaust Manifold Cracking/Leaks
- Description/Symptoms: Ticking or hissing sound, especially when the engine is cold, that disappears or lessens as the engine warms up. Reduced fuel economy, and potential for exhaust fumes to enter the cabin.
- Solution: Replace the cracked exhaust manifold. Gaskets should also be replaced at the same time.
- Estimated Cost to Fix: $800 - $1500+
- Recalls: None Found
- Oil Leaks (Valve Cover Gaskets, Rear Main Seal)
- Description/Symptoms: Visible oil leaks on the engine, oil spots on the ground, burning oil smell. Low oil level.
- Solution: Replace the valve cover gaskets or rear main seal.
- Estimated Cost to Fix: Valve cover gaskets $200 - $500, Rear Main Seal $800 - $1500+
- Recalls: None Found
Transmission
5-Speed Automatic
- Transmission Slipping/Harsh Shifting
- Description/Symptoms: Difficulty shifting gears, delayed engagement, harsh or jerky shifts, RPM flare between shifts. Often more pronounced when cold.
- Solution: Perform a transmission fluid flush and filter replacement. If the problem persists, the transmission may need to be rebuilt or replaced. In some cases, faulty solenoids can cause this.
- Estimated Cost to Fix: Fluid flush and filter replacement $200 - $400, Solenoid replacement $500-$1000, Rebuild $2500-$4500+, Replacement $3500 - $6000+
- Recalls: None Found
- Torque Converter Failure
- Description/Symptoms: Shuddering or vibration at highway speeds, especially when accelerating or going uphill. Potential for stalling, difficulty engaging gears.
- Solution: Replace the torque converter. It’s often recommended to rebuild or replace the transmission at the same time, as torque converter failure can send debris into the transmission.
- Estimated Cost to Fix: $1000 - $2500+ (depending on whether it’s just the converter or includes a transmission rebuild)
- Recalls: None Found
Suspension
- Air Suspension Compressor Failure (If Equipped)
- Description/Symptoms: Rear of the vehicle sagging, inability to maintain proper ride height, air suspension warning light illuminated. The compressor may run constantly or not at all.
- Solution: Replace the air suspension compressor. Check for leaks in the air lines and air springs as well.
- Estimated Cost to Fix: $500 - $1200+
- Recalls: None Found
- Air Spring/Bellows Leaks (If Equipped)
- Description/Symptoms: Vehicle sagging, especially after sitting overnight. Hissing sound from the air springs.
- Solution: Replace the leaking air springs/bellows.
- Estimated Cost to Fix: $400 - $800 per air spring.
- Recalls: None Found
- Front Lower Control Arm Bushing Failure
- Description/Symptoms: Clunking noise from the front suspension when going over bumps. Uneven tire wear. Steering wander.
- Solution: Replace the front lower control arms. Some aftermarket options offer replaceable bushings if the control arms are still in good condition.
- Estimated Cost to Fix: $400 - $1000+ per side
- Recalls: None Found
Electrical
- Bose Amplifier Failure
- Description/Symptoms: Loss of sound from some or all speakers. Distorted sound.
- Solution: Replace the Bose amplifier. Some owners opt to bypass the factory amplifier and install an aftermarket system.
- Estimated Cost to Fix: $500 - $1000+
- Recalls: None Found
- Door Lock Actuator Failure
- Description/Symptoms: Door lock failing to lock or unlock, requiring manual operation.
- Solution: Replace the faulty door lock actuator.
- Estimated Cost to Fix: $200 - $400+ per door
- Recalls: None Found
- Power Window Motor Failure
- Description/Symptoms: Window not moving up or down, or moving very slowly.
- Solution: Replace the power window motor.
- Estimated Cost to Fix: $200 - $400+ per window
- Recalls: None Found
Exterior
- Rear Liftgate Strut Failure
- Description/Symptoms: Rear liftgate not staying open, falling down unexpectedly.
- Solution: Replace the rear liftgate struts.
- Estimated Cost to Fix: $100 - $300+
- Recalls: None Found
Interior
- Cracked Dashboard
- Description/Symptoms: Cracking of the dashboard, especially in areas exposed to sunlight. This is a common issue due to the materials used.
- Solution: Replace the dashboard (expensive), use a dashboard cover, or apply a sealant to prevent further cracking.
- Estimated Cost to Fix: Dashboard replacement $1500 - $3000+, Dashboard cover $50 - $200
- Recalls: None Found
Summary
The 2004 INFINITI QX56, while offering a comfortable and powerful driving experience, has several known issues. Engine issues such as timing chain tensioner failure and exhaust manifold cracking can be costly to repair. Transmission issues, if left unaddressed, can lead to complete transmission failure. Suspension problems, particularly with the air suspension system, can also be expensive to fix. Electrical and interior issues are generally less severe but can still be a nuisance. Overall, potential buyers should be aware of these potential problems and factor them into their purchase decision. Pre-purchase inspections are recommended.