Positive Crankcase Ventilation: Testing and Inspection

PCV SYSTEM

Crankcase Emission Control:

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:

1. Loose hose connections
2. Missing hose clamps
3. Condition of hoses (brittle, cracked, oil soaked, collapsed, etc.)
4. Blocked passages

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.

Crankcase Ventilation Valve:

Crankcase Control Valve And Heater:

Air should pass freely through the crankcase ventilation valve. If necessary, check the inside of the valve cover area 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. If a restriction is found in the crankcase ventilation valve, the valve should be replaced.

HEATED CRANKCASE BREATHER

1. Disconnect the crankcase breather heater harness connector and separate heated crankcase breather from hoses.
2. Check the heated crankcase breather for clogging and clean with solvent if needed.
3. Using an ohm meter, measure the resistance between heated crankcase breather connector terminals 1 and 2.

Resistance: 4 - 17 Ohms

4. If resistance is not within specification, replace heated crankcase breather.
5. Turn the ignition switch "ON".
6. Using a volt meter, measure the voltage at heated crankcase breather harness connector terminals 1 and 2.

Voltage: System Voltage

7. If voltage is not to specification, check wiring and connectors for looseness or breaks. refer to CHASSIS ELECTRICAL DIAGRAMS