Q: What is the purpose of a Positive Crankcase Ventilation (PCV) system and PCV Valve for Cadillac ElDorado and Fleetwood?
A: Instead of venting them to the atmosphere, a positive crankcase ventilation (PCV) system is used to consume crankcase vapors in the combustion process. In gasoline engines, small amounts of combustion gas pass by the piston rings and get into the crankcase. Such crankcase blow-by gases have unwanted air pollutants, which are hydrocarbons. The PCV system is used to keep these vapors from getting away into the atmosphere while still allowing for adequate ventilation of the crankcase that ensures good oil quality. It should be checked every time you change oil and serviced every 48,000 kilometers (30,000 miles). For it can be damaged, never run an engine without a PCV valve or a ventilation system. Beginning with locating PCV valve usually found either in valve cover or intake manifold and then disconnecting the crank case ventilation tube from the positive crank case ventilation valve followed by removing the PCV valve from its grommet, install PCV valve by having it inserted into grommet with connecting ventilation tube to PCV valve.