Chevrolet Sonic manuals

Chevrolet Sonic Repair Manual: Crankcase Ventilation System Inspection/Diagnosis

Chevrolet Sonic Repair Manual / Powertrain / Engine / Emissions / PCV / 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:

  1. Remove the PCV hose from the cylinder head cover.
  2. Operate the engine at idle.
  3. 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:

    Inflatable Restraint Sensing and Diagnostic Module Programming and Setup
    Special Tools EL-49642 SPS Programming Support Tool For equivalent regional tools, refer to Special Tools. Note: DO NOT program a control module unless directed to by a service procedure or a service bulletin. If the ECU is not properly configured with the correct calibration ...

    Front Wheel Drive Intermediate Shaft Replacement
    Front Wheel Drive Intermediate Shaft Replacement Callout Component Name Preliminary Procedure Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle. Remove the wheel drive shaft assembly from the vehicle ...

    SIR Service Precautions
    General Service Instructions Warning: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling . Failure to observe the correct procedure could cause deployment of the SIR components, person ...

    © 2014-2019 Copyright www.csmans.com