Chevrolet Sonic Repair Manual: Crankcase Ventilation System Inspection/Diagnosis
- Results of Incorrect Operation
-
A plugged positive crankcase ventilation (PCV) orifice or hose may cause the following conditions:
- Rough idle
- Stalling or slow idle speed
- Oil leaks
- Oil in the throttle body
- Sludge in the engine
- Functional Check
-
With these systems, any blow-by in excess of the system capacity, from a badly worn engine, sustained heavy load, etc., is exhausted into the throttle body and is drawn into the engine.
Proper operation of the crankcase ventilation system depends upon a sealed engine. If oil slugging or dilution is noted and the crankcase ventilation system is functioning properly, check the engine for a possible cause. Correct any problems.
If an engine is idling rough, inspect for a clogged PCV orifice, a dirty vent filter, air cleaner element, or plugged hose. Replace as required. Use the following procedure:
- Remove the PCV hose from the cylinder head cover.
- Operate the engine at idle.
- Place your thumb over the end of the hose in order to check for a vacuum. If there is no vacuum at the hose, inspect for the following items:
- Plugged hoses
- The manifold port
- Turn OFF the engine.
- Inspect the PCV orifice in the cylinder head cover for debris or blockage.
PCV
...
Positive Crankcase Ventilation Hose/Pipe/Tube Replacement
Removal Procedure
Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct
Replacement.
Open the 2 positive crankcase ventilation pipe retainer clips ...
Other materials:
Hood Primary Latch Release Cable Replacement
iv
Hood Primary Latch Release Cable Replacement
Callout
Component Name
Preliminary Procedures
Remove the radiator opening upper cover. Refer to Front Opening
Upper Cover Replacement.
Remove the air inlet grille. Refer to A ...
Aluminum Wheel Refinishing
Finish Damage Evaluation Procedure
Note:
If the wheels are chrome-plated, do not re-plate or refinish
the wheels.
If the wheels are polished aluminum, do not refinish the wheels
in the dealer environment. Utilize a refinisher that meets manufacturer
...
Heated Oxygen and Oxygen Sensor Caution
Caution: Do not remove the pigtail from either the heated oxygen sensor
(HO2S) or the oxygen sensor (O2S). Removing the pigtail or the connector will
affect sensor operation.
Handle the oxygen sensor carefully. Do not drop the HO2S. Keep the in-line
electrical connector and the louver ...
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