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:

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:

Tread Wear Indicators Description
The original equipment tires have tread wear indicators that show when you should replace the tires. The location of these indicators are at 60 degree intervals around the outer diameter of the tire. The indicators appear as a 6 mm (0.25 in) wide band when the tire trea ...

Throttle Body Heater Outlet Hose Replacement (LUW)
Throttle Body Heater Outlet Hose Replacement Callout Component Name Preliminary Procedure Drain the cooling system. Refer to Cooling System Draining and Filling. Remove the air cleaner outlet duct. Refer to Air Cleaner Out ...

Secondary Air Injection Check Valve Replacement
Secondary Air Injection Check Valve Replacement Callout Component Name 1 Secondary Air Injection Outlet Pipe Note: Squeeze the retainer on opposite sides to release. 2 Seconda ...

0.0053