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P3654

GDI Carbon Buildup Detected - Intake Valve Performance

2004-2008 Chrysler Crossfire 3.2L V6

Moderate SeverityPowertrainGeneric (SAE)

Description

The PCM has detected a pattern consistent with carbon buildup on the intake valves. GDI engines are prone to intake valve deposits since fuel does not wash over the valves.

Symptoms

  • Rough idle that worsens over time
  • Misfires at cold start
  • Reduced power
  • Poor fuel economy
  • Engine vibration
  • Cold start stumble

Common Causes

  • Normal carbon accumulation from PCV gases
  • Excessive short-trip driving
  • Oil consumption past valve seals
  • Low-quality fuel
  • Lack of intake valve cleaning maintenance

Diagnostic Steps

  1. Perform relative compression test
  2. Monitor long-term fuel trims per cylinder
  3. Inspect intake valves with borescope
  4. Check PCV system operation
  5. Review driving habits and mileage

Repair Notes

Perform intake valve walnut shell blasting or chemical cleaning. Install oil catch can to reduce future buildup. Consider intake valve cleaning every 60,000 miles on GDI engines.

Related Codes

P3650GDI High-Pressure Fuel Pump PerformanceP3653GDI Injector Circuit Malfunction - Cylinder Specific

Other Powertrain Codes

P3654 on Other Vehicles

Common Questions

What does code P3654 mean on a 2004-2008 Chrysler Crossfire?

P3654 stands for "GDI Carbon Buildup Detected - Intake Valve Performance". The PCM has detected a pattern consistent with carbon buildup on the intake valves. GDI engines are prone to intake valve deposits since fuel does not wash over the valves.

What are the symptoms of P3654 on a Chrysler Crossfire?

Common symptoms of P3654 include: Rough idle that worsens over time, Misfires at cold start, Reduced power, Poor fuel economy, Engine vibration, Cold start stumble.

What causes P3654 on a 2004-2008 Chrysler Crossfire?

Common causes of P3654 include: Normal carbon accumulation from PCV gases, Excessive short-trip driving, Oil consumption past valve seals, Low-quality fuel, Lack of intake valve cleaning maintenance.

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