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
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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:
Dimensions - Body (4NB)
Point-to-point measurements are for reference only. All measurements are given
in millimeters. Use these measurements for diagnosing and estimating. Point-to-point
measurements are duplicated with tram bar pointers set at equal lengths. All die
marks, holes, slots, and fasteners are measured t ...
Floor Panel Carpet Replacement
Floor Panel Carpet Replacement
Callout
Component Name
Preliminary Procedures
Remove front seats. Refer to Driver or Passenger Seat Removal and
Installation.
Remove rear seat cushion. Refer to Rear Seat Cushion Removal and ...
Secondary Air Injection Pump Removal
Disconnect the secondary air injection pump pipe (3). Refer to Plastic Collar
Quick Connect Fitting Service.
Remove the secondary air injection pump nut (2) and the 2 secondary air
injection pump bolts (4).
Remove the secondary air injection pump (1 ...
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