The Positive Crankshaft Ventilation Valve (PCV) is used to reduce the amount of emissions a vehicle releases into the atmosphere. When clogged, the engine can develop many problems, including an oil leak.
PCV valve operation
During combustion, some of the exhaust gases pass around the piston ring instead of exiting the exhaust valve. When the exhaust pressure inside the engine reaches a certain point, the PCV valve opens and returns the exhaust gases to the combustion chamber. Without a PCV system, these would go into the atmosphere bypassing the exhaust.
A clogged PCV valve
When a PCV valve stops working, pressure builds up inside its cover. This can cause many engine problems, including an oil leak, particularly at the valve bowl gasket. Clogged PCV valves cause the engine to run poorly, use more fuel and emit more exhaust gases.
PCV valve replacement
Replacing a PCV valve in most vehicles requires no tools, although tweezers can make the job easier. The valve simply slides out of its assembly and the hose attached to it as well. A valve is inserted into its place and the hose is reconnected. If necessary, motor oil can be used to lubricate it a bit and make insertion easier.
