Background

In cars equipped with the PCV valve, its purpose is to regulate the flow of blow-by gasses from the crankcase into the intake manifold, where they are re-burned in the cylinders. The design of this valve is critical for proper crankcase ventilation and idle performance. From the following reference:

"During normal compression stroke, a small amount of gasses in the combustion chamber escapes past the piston. Approximately 70% of these "blow-by" gasses are unburned fuel (hydrocarbons) that can dilute and contaminate the engine oil, cause corrosion to critical parts, and contribute to sludge build up. At higher engine speeds, blow-by gasses increase crankcase pressure that can cause oil leakage from sealed engine surfaces."

"The purpose of the Positive Crankcase Ventilation (PCV) system is to remove these harmful gasses from the crankcase before damage occurs and combine them with the engine's normal incoming air/fuel charge."

These instructions were performed on a 2004 Honda S2000 (AP2 2004-2009). The same instructions can be applied to AP1 but please verify the part numbers.

Comments

• You can replace the PCV Valve or clean it using WD40 / brake cleaner / carb cleaner.
• I also replaced the PCV Hose to be on the safe side since the car is over 12 years old.
• Parts online will be listed under the System Name / Component: Breather Tube.