2004 Pontiac Grand Prix

The 2004 Pontiac Grand Prix was a mid-size sedan known for its sporty styling and available supercharged engine. Engine options included a 3.1L V6 producing 175 horsepower and 195 lb-ft of torque, a 3.8L V6 producing 200 horsepower and 225 lb-ft of torque, and a supercharged 3.8L V6 producing 260 horsepower and 280 lb-ft of torque. All engines were paired with a 4-speed automatic transmission. Owners often praised its comfortable ride, spacious interior, and powerful supercharged engine. Common complaints included issues with the electrical system, particularly the window motors, and some transmission problems.

Engine

3.1L V6

• Intake Manifold Gasket Leak
  • Description/Symptoms: Coolant leak, overheating, white smoke from the exhaust, poor fuel economy.
  • Solution: Replace the intake manifold gasket.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found
• Coolant elbows leaking
  • Description/Symptoms: Coolant leak, overheating, low coolant levels
  • Solution: Replace the coolant elbows.
  • Estimated Cost to Fix: $100 - $300+
  • Recalls: None Found

3.8L V6 (Naturally Aspirated and Supercharged)

• Lower Intake Manifold Gasket Failure
  • Description/Symptoms: Coolant leak, overheating, rough idle, white smoke from exhaust.
  • Solution: Replace the lower intake manifold gasket and potentially the upper intake manifold.
  • Estimated Cost to Fix: $400 - $800+
  • Recalls: None Found
• Crankshaft Position Sensor Failure
  • Description/Symptoms: Engine stalling, no start condition, check engine light illuminated.
  • Solution: Replace the crankshaft position sensor.
  • Estimated Cost to Fix: $100 - $250+
  • Recalls: None Found
• Mass Airflow Sensor (MAF) Failure (Supercharged Only)
  • Description/Symptoms: Poor acceleration, rough idle, reduced fuel economy, check engine light.
  • Solution: Clean or replace the MAF sensor.
  • Estimated Cost to Fix: $100 - $300+
  • Recalls: None Found

Transmission

4T65-E (All Engines)

• Hard Shifting/Slipping
  • Description/Symptoms: Harsh or delayed shifting between gears, transmission slipping, particularly between 2nd and 3rd gear, and potential complete failure.
  • Solution: Often requires a complete transmission rebuild or replacement. In some cases, a valve body replacement may alleviate the issue.
  • Estimated Cost to Fix: $1,800 - $3,500+
  • Recalls: None Found
• Torque Converter Clutch (TCC) Failure
  • Description/Symptoms: Shuddering at highway speeds, erratic engine RPMs, check engine light (TCC error code).
  • Solution: Replace the torque converter or rebuild the transmission.
  • Estimated Cost to Fix: $1,200 - $2,500+
  • Recalls: None Found

Suspension

• Front Strut Mount Failure
  • Description/Symptoms: Clunking noise from the front suspension, especially over bumps, poor handling.
  • Solution: Replace the front strut mounts.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found
• Rear Suspension Sagging (Especially models with the “sport” suspension)
  • Description/Symptoms: Rear of the vehicle sitting lower than normal, particularly when loaded, reduced ride quality.
  • Solution: Replace the rear shocks and/or springs.
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found

Electrical

• Power Window Motor Failure
  • Description/Symptoms: Window not operating, slow window movement, clicking noise from the door panel.
  • Solution: Replace the power window motor.
  • Estimated Cost to Fix: $150 - $400+ per window
  • Recalls: None Found
• Passlock System Issues
  • Description/Symptoms: Vehicle not starting, security light illuminated, system requires a lengthy reset procedure.
  • Solution: Replace or reprogram the Passlock sensor or related components.
  • Estimated Cost to Fix: $100 - $400+
  • Recalls: None Found
• Body Control Module (BCM) Issues
  • Description/Symptoms: Intermittent electrical issues, such as lights not working, power door locks malfunctioning, or issues with the instrument cluster.
  • Solution: Reprogram or replace the BCM.
  • Estimated Cost to Fix: $300 - $700+
  • Recalls: None Found
• Headlight Dimming/Flickering
  • Description/Symptoms: Headlights dimming or flickering, especially at idle.
  • Solution: Check and clean ground connections, replace headlight bulbs, or in some cases, replace the headlight switch.
  • Estimated Cost to Fix: $50 - $200+
  • Recalls: None Found

Exterior

• Door Handle Breakage
  • Description/Symptoms: Outer door handles breaking, particularly in cold weather.
  • Solution: Replace the door handle.
  • Estimated Cost to Fix: $50 - $200+ per handle
  • Recalls: None Found

Interior

• Headliner Sagging
  • Description/Symptoms: Headliner fabric detaching from the roof and sagging.
  • Solution: Replace or re-glue the headliner.
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found

Summary

The 2004 Pontiac Grand Prix, while a popular and stylish car, has a number of common issues to watch out for. Engine problems, particularly intake manifold leaks, are prevalent and can be costly. Transmission issues, especially with the 4T65-E, are another major concern and can lead to expensive repairs. Electrical problems, such as window motor and Passlock failures, are also common annoyances. The severity of these issues ranges from relatively minor to potentially catastrophic, with repair costs varying accordingly. Potential buyers should thoroughly inspect the vehicle and address any identified problems before purchasing.