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:
Parking Brake Cable Replacement (Drum Brake)
Removal Procedure
Remove the front floor console. Refer to Front Floor Console Replacement.
Ensure that the parking brake lever is in the fully released position.
Using ONLY HAND TOOLS, remove the adjusting nut (1) from the end of
the front park bra ...
Knock Sensor System Description
Circuit/System Description
The knock sensor system enables the engine control module (ECM) to control
the ignition timing for the best possible performance while protecting the engine
from potentially damaging levels of detonation. The ECM uses the knock sensor
system to test for ...
Electronic Park Lock Description and Operation
If the vehicle is equipped with automatic transmission and a floor mounted console
gear shift, it has an electronic park lock system (EPL). The EPL system purpose
is to prevent the ignition key from being turned to the OFF position when the transmission
is in any position other than PARK and t ...
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