Chevrolet Sonic Repair Manual: Crankcase Ventilation System Inspection/Diagnosis
- Results of Incorrect Operation
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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
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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:
Operation
Radio Controls without Touchscreen
The infotainment system is operated by using the pushbuttons, multifunction
knobs, menus shown on the display, and steering wheel controls, if equipped.
Turning the System On or Off
O /VOL (Power/Volume)
Press to turn t ...
Airbag Sensing and Diagnostic Module Replacement
Airbag Sensing and Diagnostic Module Replacement
Callout
Component Name
Warning: Refer to SIR Warning.
Warning: Do not strike or jolt the inflatable restraint sensing
and diagnostic module (SDM). Before apply ...
Electronic Ignition System Description
Electronic Ignition System Operation
The electronic ignition system produces and controls the high energy secondary
spark. This spark ignites the compressed air/fuel mixture at precisely the correct
time, providing optimal performance, fuel economy, and control of exhaust emissions.
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