If the crankcase ventilation system is not functioning at Chevrolet Cobalt (for example, an increased oil flow), the valve of the system should be checked and cleaned. To do this:
1) Remove the ignition cap.
(2) A mounting lock of the crankcase gases shall be clamps and disconnected from the valve.
(3) The key "on 23" unscrew the valve from the hole in the cover of the GBV.
(4) The valve shall be removed and again connected to it from the crankcase.
(5) The engine shall be started and the valve outlet shall be closed; a vacuum shall be felt.
6) Insert a thin rod in the hole and press it to check the flow of the plunger in the valve.
(7) If the plunger is moved with difficulty, it must be cleaned. Use liquid to clean the carburettors.
(8) Install everything in place.