Genuine Chevrolet Express PCV Valve

Chevrolet Express PCV Valve Parts Questions & Answers

• Valve Asm,Pcv
  19303069
  Q: What is the purpose of the Positive Crankcase Ventilation (PCV) system and PCV Valve on Chevrolet Express?

  A: To reduce hydrocarbon emissions, the Positive Crankcase Ventilation (PCV) system scavenges crankcase vapors rich in unburned hydrocarbons. Rather than using intake manifold vacuum for this purpose, as it happens in the conventional PCV systems; however, the system in these vehicles does not. It is done by connecting a fresh air inlet hose from the air intake duct or resonator box straight to valve cover, which allows pressure equalization by fresh air. There is another hose that draws in crankcase vapors by connecting the left valve cover to the intake manifold. Based on intake vacuum levels, PCV valve controls vapor flow into intake manifold. The engine model determines how a particular PCV system is configured. When servicing an engine, the hoses of its PCV system should be checked for any damage or clogs as well as leaks. Rough idling, stalling, high or low idle speeds, oil leaks and sludge buildup may all occur due to blocked or leaking hoses. Vacuum presence in the PCV hose can be tested very simply checking vacuum gauge readings at different stages of running and diagnosing such problems as leaks blockages or excessive crankcase pressure which influence PCV system work.