CCV Valve Failure

CCV Valve Failure

The Crankcase Ventilation (CCV) system recirculates blow-by gases from the crankcase back into the intake. The valve and hoses deteriorate with age.

Symptoms

• Oil consumption increase
• Rough idle
• Oil in intake boot (remove boot and check)
• Whistling noise from engine
• Lean fault codes (P0171, P0174) due to vacuum leaks
• Oil leaks from valve cover or oil cap

Diagnosis

1. Remove intake boot and check for oil accumulation
2. Inspect CCV hoses for cracks or collapse
3. Check for vacuum at oil cap (remove cap at idle — should have slight suction)
4. If cap blows off or no suction, CCV is likely failed

Replacement

The CCV valve is located under the intake manifold, requiring manifold removal for access:

1. Remove intake manifold
2. Replace CCV valve and all associated hoses
3. Replace intake manifold gaskets
4. Reinstall manifold — torque bolts to 10 Nm