Part and system guide

PCV Valve

The PCV valve controls crankcase vapor flow into the intake.

What it does

Ventilates blow-by gases so pressure does not build in the crankcase.

Failure signs

  • Oil leaks
  • Rough idle
  • Whistling noise
  • Increased oil consumption
  • Sludge or moisture buildup

Maintenance notes

  • Use the correct PCV part and hose routing.
  • Inspect hoses for collapse or sludge.
  • A stuck PCV valve can create vacuum leaks or crankcase pressure.