PCV Valve

There are two 4 cylinders available in the 98 Cavalier, a 2.2L and a 2.4L. Neither of which have a PCV valve, or require positive crankcase ventilation system maintenance. Since I don't know the exact engine size, and the descriptions of operation differ slightly, I will paste both versions. The first is for 2.2L engines;
Crankcase Ventilation System Description
General Description
A crankcase ventilation system is used to provide scavenging of the crankcase vapors. Blow-by gases are passed through a crankcase ventilation oil/air separator into the air cleaner outlet resonator. The oil/air separator is inside the valve rocker arm cover and allows any scavenged oil to be returned to the crankcase.

Operation
The only flow through the oil/air separator is the combustion blow-by, as there is no fresh air inlet to the crankcase. The primary flow of blow-by into the separator is through the openings inside the valve rocker arm cover. The oil/air separator causes oil, which may be suspended in the blow-by gases, to be separated and drain back to the crankcase. The blow-by gases are then drawn into the air cleaner outlet resonator by normal engine vacuum and burned in the combustion process.

And 2.4L;
1998 Chevrolet Cavalier | Cavalier, Sunfire (VIN J) Service Manual | Engine | Document ID: 192483

Crankcase Ventilation System Description
General Description
A crankcase ventilation system is used to provide scavenging of the crankcase vapors. Blow-by gases are passed through a crankcase ventilation oil/air separator into the air cleaner outlet resonator. The oil/air separator is mounted to the engine block and allows any scavenged oil to be returned to the crankcase.

Operation
The only flow through the oil/air separator is the combustion blow-by, as there is no fresh air inlet to the crankcase. The primary flow of blow-by into the separator is through a hose from the timing chain housing. The oil/air separator causes oil, which may be suspended in the blow-by gases, to be separated and drain back to the crankcase. The blow-by gases are then drawn into the air cleaner outlet resonator by normal engine vacuum and burned in the combustion process.

There should be a crankcase vent tube on the valve cover going to the intake and it should be there but I dont have a car infront of me to check

jim

Best I could do is call up to hq to see

Its located in the center of the rear valve cover. When replacing it make sure not to pull the hose off of the intake manifold because its hard to get it back on. Hope this helps