Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
PCV System: Operation
Blow-by gases from the crankcase are routed to an oil separator, then drawn through one of 2 circuits into the engine. The upper circuit hose with a .2" (5 mm) orifice leads to a throttle body port just downstream from the airflow sensor.
The lower circuit leads to the intake manifold and is connected to the fuel evaporation system. A .07" (2 mm) orifice is used near the oil separator, and a .08" (2 mm) orifice is provided in the hose to the carbon canister.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.