Honda Civic/Del Sol 1996-2000

Positive Crankcase Ventilation (PCV) Valve


The Positive Crankcase Ventilation (PCV) valve is part of a system, which is designed to protect the atmosphere from harmful engine blow-by gas vapors. Blow-by gas from the crankcase, as well as fumes from crankcase oil, are diverted into the combustion chamber where they are burned during engine operation. Proper operation of this system is necessary for optimal engine performance, and decreases the amount of harmful vapors released into the atmosphere.

All models covered are equipped with a Positive Crankcase Ventilation (PCV) system in which blow-by gas is returned to the combustion chamber through the air intake system.

The PCV valve should be checked according to the manufacturer's recommendations. Most models every 60,000 miles or 4 years, whichever occurs first. Although there is not an official manufacturer's recommendation for the remaining model years, checking the PCV valve is a simple task, most professionals would recommend checking the valve during tune-ups. Two consequences of a failed PCV valve are the possibility of an intake vacuum leak which could cause erratic engine running conditions, or the inability of the crankcase to adequately vent combustion blow-by gasses causing potential oil leaks.


  1. Check the PCV valve, hoses, and seal for leakage. Replace any component found to be leaking.
  3. With the engine at operating temperature and idling, carefully pinch the hose between the PCV valve and the air intake system. When the hose is pinched closed, a clicking sound should be heard.
  5. If a clicking sound is heard, the valve is operating properly. If no clicking noise is heard, replace the PCV valve mounting grommet and inspect the vacuum hose for a vacuum leak. Replace any part that is found to leak.

With the PCV valve removed, a rattling noise should be heard if the valve is shaken vigorously.

  1. Pinch the PCV valve hose again. If a clicking sound is not present, replace the PCV valve.


  1. The PCV valve is mounted in a rubber grommet, which is usually seated in the intake manifold and has a hose connected to it from the crankcase breather chamber.
  3. Before removing the valve, thoroughly clean the area surrounding the valve.
  5. Remove the valve by carefully lifting the valve away from the sealing grommet and the manifold.
  7. Once the valve is removed check for loose, disconnected or deteriorated lines or hoses and replace if necessary. Make sure the hoses are clean and free of debris. Clean them with a safe solvent, if necessary.

To install:

  1. To install the PCV valve, coat the mounting grommet with a light coating of engine oil, press the valve into the grommet, and reinstall the vacuum line and clamp.