Crankcase ventilation system
The function of the crankcase ventilation system is to reduce the emission of unburned hydrocarbons in gases that break through into the crankcase and to minimize the formation of oil sludge.
On HCS engines, the system consists of an oil filler vent head (with integral filter) and a hose connecting the engine breather valve to the back of the air cleaner housing.
On CVH engines, a closed crankcase ventilation system is used, the function of which is basically the same as for HCS engines, but the ventilation hose is connected directly to the cylinder head cover. A separate filter is installed in the hose to the head cover.
The systems installed on the Endura-E and PTE engines are similar to those used on the HES and CVH engines, but with a different hose arrangement to connect the remotely located air cleaner and fuel injection system.
On Zetec and Zetec-E engines, the main components of the crankcase ventilation system are the oil separator, mounted on the front side of the cylinder block, and the Positive Crankcase Ventilation (PCV), a set of valves located at the upper left end of the separator.
The connection consists of a PCV tube and two flexible hoses connecting the PCV valve to the fitting on the left front end of the intake manifold, and a PCV hose connecting the cylinder head cover to the air cleaner housing.
On HCS engines, remove and inspect the oil filler cap to ensure it is in good condition and free of contamination.
With the air cleaner element removed, wipe the housing clean and, on Zetec engines, remove the small filter from its seat in the rear right-hand corner of the housing. If the filter is contaminated with thickened oil, it should be cleaned in a suitable solvent, dried and reinstalled (see Fig. 1.30).
[The original version can be found on the website: FORDBOOK.RU]