Replacing The Pcv Valve on a Honda S2000 AP2
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.
- 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.
PCV Valve Removal
Locate the PCV Valve on the driver side of valve cover.
Using pliers, loosen the hose clamp and move it farther down the hose. If replacing the hose, repeat at the opposite end.
Pull the hose off of the PCV valve. If replacing the hose, repeat at the opposite end.
Note: This took majority of my time as it was sealed on pretty tight. Try wiggling it and turning it. I resorted to using vice gripes to twist it off and a small screw driver to pry it since I was replacing the hose.
Remove PCV valve using 17mm Deep Socket Well (counter-clockwise).
PCV Valve Cleaning
Clean the inner valve with WD40, brake cleaner or similar solvent.
Clean the outer part that attaches to the silicon tubing with rubbing alcohol.
Shake the PCV valve, you should hear rattling. If not, purchase a new one.
Place 14mm Crusher Washer on PCV Valve threads and torque to 44N/m (33lb/ft).
Reattach the hose to the PCV Valve.
Using pliers, loosen the hose clamps and return them to their original position.
PCV Valve Verification
Start car and at idle, pinch the PCV valve tube until you here a clicking sound. If there is no clicking sound, recommend replacing the PCV valve and tubing.
There is no scheduled in replacing the PCV valve. If you want to be on the safe side, I recommend inspecting and cleaning it every other oil change.
PCV Valve 44N/m (33lb/ft)