2003 Pontiac Grand Prix

The 2003 Pontiac Grand Prix was a popular mid-size car known for its sporty styling and comfortable ride. Engine options included a 3.1L V6, a 3.8L V6, and a supercharged 3.8L V6. The 3.8L V6 produced 200 horsepower and 225 lb-ft of torque, offering a good balance of power and fuel economy. Many owners appreciated the car’s spacious interior and trunk, as well as its available features like the head-up display. Common complaints included issues with the car’s electrical system and some drivetrain components, as well as the plastic intake manifold gaskets on some of the engines. All engine options were paired with a 4T65-E 4-speed automatic transmission.

Engine

3.1L V6

• Intake Manifold Gasket Failure
  • Description/Symptoms: Coolant leak, overheating, white smoke from the exhaust, engine misfires.
  • Solution: Replace the intake manifold gaskets with updated parts.
  • Estimated Cost to Fix: $300 - $600

Recalls: None Found

3.8L V6 (Non-Supercharged)

• Intake Manifold Gasket Failure
  • Description/Symptoms: Coolant leak, overheating, white smoke from the exhaust, engine misfires.
  • Solution: Replace the intake manifold gaskets with updated parts.
  • Estimated Cost to Fix: $300 - $600
  • Recalls: None Found
• Fuel Injector Failure
  • Description/Symptoms: Engine misfires, rough idle, poor fuel economy, check engine light.
  • Solution: Replace the faulty fuel injector(s).
  • Estimated Cost to Fix: $150 - $400+ (depending on the number of injectors replaced)
  • Recalls: None Found

3.8L V6 (Supercharged)

• Supercharger Failure
  • Description/Symptoms: Loss of power, whining noise from the supercharger, check engine light.
  • Solution: Rebuild or replace the supercharger.
  • Estimated Cost to Fix: $800 - $2500+
  • Recalls: None Found
• Intercooler Pump Failure
  • Description/Symptoms: Reduced supercharger performance, overheating under boost, check engine light.
  • Solution: Replace the intercooler pump.
  • Estimated Cost to Fix: $200 - $400
  • Recalls: None Found

Transmission

4T65-E (All Engines)

• Harsh Shifting/Slipping
  • Description/Symptoms: Hard shifts between gears, especially 2nd to 3rd, transmission slipping, delayed engagement.
  • Solution: Rebuild or replace the transmission. Can sometimes be addressed by replacing the valve body or solenoids.
  • Estimated Cost to Fix: $1800 - $3500+
  • Recalls: None Found
• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibration, especially at low speeds, stalling, check engine light.
  • Solution: Replace the torque converter.
  • Estimated Cost to Fix: $800 - $1500
  • Recalls: None Found

Suspension

• Strut Mount Failure
  • Description/Symptoms: Clunking noise from the front suspension, especially when turning, poor handling.
  • Solution: Replace the strut mounts.
  • Estimated Cost to Fix: $200 - $400+ per side
  • Recalls: None Found
• Rear Air Suspension Compressor Failure (if equipped)
  • Description/Symptoms: Rear of the car sagging, compressor not running, suspension warning light.
  • Solution: Replace the air suspension compressor.
  • Estimated Cost to Fix: $300 - $600
  • Recalls: None Found

Electrical

• Power Window Motor Failure
  • Description/Symptoms: Window not going up or down, slow or erratic movement.
  • Solution: Replace the power window motor.
  • Estimated Cost to Fix: $150 - $300 per window
  • Recalls: None Found
• Body Control Module (BCM) Issues
  • Description/Symptoms: Intermittent electrical problems, such as lights not working, door locks malfunctioning, or security system issues.
  • Solution: Diagnose and potentially replace the BCM. Requires programming.
  • Estimated Cost to Fix: $300 - $800+
  • Recalls: None Found
• Headlight Switch Failure
  • Description/Symptoms: Headlights not working properly, intermittent headlight function, dimmer switch malfunction.
  • Solution: Replace the headlight switch.
  • Estimated Cost to Fix: $100 - $200
  • Recalls: None Found

Exterior

• Door Handle Breakage
  • Description/Symptoms: Door handle breaking easily, especially in cold weather.
  • Solution: Replace the door handle with an aftermarket option.
  • Estimated Cost to Fix: $50 - $150 per handle
  • Recalls: None Found

Interior

• Headliner Sagging
  • Description/Symptoms: Headliner fabric detaching from the roof.
  • Solution: Replace or re-glue the headliner.
  • Estimated Cost to Fix: $200 - $500
  • Recalls: None Found
• Digital Instrument Panel Failure (If Equipped)
  • Description/Symptoms: Display fading, pixel loss, or complete failure of the digital instrument panel.
  • Solution: Repair or replace the instrument panel.
  • Estimated Cost to Fix: $200 - $600+
  • Recalls: None Found

Summary

The 2003 Pontiac Grand Prix can be a reliable car, but it is important to be aware of common issues, especially considering its age. Engine issues, such as intake manifold gasket failures, are relatively common and can lead to more serious problems if not addressed. Transmission issues, while not always present, can be costly to repair. Electrical gremlins are also a possibility. The severity of these issues ranges from minor inconveniences to major repairs. The cost to fix these issues can vary widely, but potential buyers should factor these expenses into their budget. The 3.8L supercharged version tends to have some additional wear parts that can become issues as the vehicle gets older.