Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Positive Crankcase Ventilation: Testing and Inspection

Crankcase Ventilation Closed Throttle:






1. The integrity of the PCV system is critical to the proper functioning of the fuel system. Before making major adjustments or replacing components in the fuel system check the PCV system for:
^ Loose hose connections
^ Missing hose clamps
^ Condition of hoses (brittle, cracked, oil soaked, collapsed, etc.)
^ Blocked passages
2. Any hose or fitting found to be weak, collapsed or broken should be replaced with an approved fuel/fuel-vapor type hose. Any other type of hose material is not suitable for PCV system use.
3. If necessary, check the calibrated orifice in the throttle body where the PCV connections are for sludge build-up that could interfere with crankcase vapor return. Should this area become clogged, high crankcase pressure would result and cause abnormal amounts of oil leakage from some or all engine gaskets and seals. Clean passages as necessary.