2002 Pontiac Bonneville

The 2002 Pontiac Bonneville was a full-size sedan known for its comfortable ride and spacious interior. Engine options included a 3.8L V6 (L36 and L67 supercharged). The L36 produced around 205 horsepower and 230 lb-ft of torque. People generally liked the Bonneville for its smooth ride and ample power from the V6, but some disliked its somewhat dated styling and occasional electrical gremlins.

Engine

3.8L L36 V6

• Intake Manifold Gasket Failure
  • Description/Symptoms: Coolant leak, often external, leading to overheating. White smoke from the exhaust is also a potential symptom.
  • Solution: Replacement of the intake manifold gaskets with an updated design.
  • Estimated Cost to Fix: $300 - $600
  • Recalls: None Found
• Coolant Elbow Leak
  • Description/Symptoms: Plastic coolant elbows degrade and crack, causing coolant leaks.
  • Solution: Replace the plastic elbows with aluminum ones.
  • Estimated Cost to Fix: $50 - $150
  • Recalls: None Found

3.8L L67 Supercharged V6

• Supercharger Failure
  • Description/Symptoms: Whining noise from the supercharger, loss of power, potential bearing failure.
  • Solution: Supercharger rebuild or replacement.
  • Estimated Cost to Fix: $500 - $1500+
  • Recalls: None Found
• Intercooler Leaks
  • Description/Symptoms: Coolant loss, reduced supercharger performance, potential overheating.
  • Solution: Intercooler repair or replacement.
  • Estimated Cost to Fix: $300 - $800
  • Recalls: None Found

Transmission

4T65-E (All Engines)

• Pressure Control Solenoid Failure
  • Description/Symptoms: Harsh shifting, slipping between gears, erratic shifting patterns.
  • Solution: Replacement of the pressure control solenoid.
  • Estimated Cost to Fix: $200 - $500
  • Recalls: None Found
• Torque Converter Clutch (TCC) Failure
  • Description/Symptoms: Shuddering at highway speeds, especially when the TCC engages. Can also cause stalling.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $400 - $800
  • Recalls: None Found

Suspension

• Front Strut Mount Failure
  • Description/Symptoms: Clunking noise from the front suspension, especially when going over bumps. Poor handling.
  • Solution: Replacement of the strut mounts.
  • Estimated Cost to Fix: $200 - $400
  • Recalls: None Found
• Rear Air Ride Suspension Issues (If Equipped)
  • Description/Symptoms: Sagging rear end, failure of the air compressor, leaks in the air lines or air springs.
  • Solution: Replacement of the air springs, compressor, or repair of the air lines. Some owners convert to traditional coil springs.
  • Estimated Cost to Fix: $300 - $1000+ depending on components.
  • Recalls: None Found

Electrical

• Body Control Module (BCM) Issues
  • Description/Symptoms: Intermittent electrical problems, such as malfunctioning power windows, door locks, or lighting. Can also cause issues with the security system.
  • Solution: BCM replacement or reprogramming.
  • Estimated Cost to Fix: $200 - $600+
  • Recalls: None Found
• Ignition Control Module (ICM) Failure
  • Description/Symptoms: Engine misfires, stalling, or failure to start.
  • Solution: ICM replacement.
  • Estimated Cost to Fix: $150 - $300
  • Recalls: None Found

Exterior

• Headlight Housing Clouding/Yellowing
  • Description/Symptoms: Headlights appear dim due to clouding or yellowing of the plastic lens.
  • Solution: Headlight restoration kit or headlight replacement.
  • Estimated Cost to Fix: $20 - $200
  • Recalls: None Found

Interior

• Power Window Regulator Failure
  • Description/Symptoms: Window operates slowly or not at all. Grinding noises when operating the window.
  • Solution: Window regulator replacement.
  • Estimated Cost to Fix: $150 - $350
  • Recalls: None Found

Summary

The 2002 Pontiac Bonneville, while a comfortable car, does have its share of common problems. Engine issues such as intake manifold gasket leaks (especially in the L36) and supercharger problems (in the L67) can be costly to repair. Transmission issues with the 4T65-E are also prevalent. Electrical problems, particularly with the BCM, can be difficult to diagnose and fix. Suspension issues, particularly with the optional air ride system, can also add to the ownership cost. Overall, potential buyers should be aware of these common issues and factor in potential repair costs when considering this vehicle. The severity of these issues ranges from minor inconveniences to major repairs, with costs ranging from a few dollars for a simple fix to several hundred or even thousands for more extensive work.