Nissan Patrol, Ford Maverick

1988-1997 of release

Repair and operation of the car

Nissan Patrol and Ford Maverik
+ Cars of the Nissan Patrol and Ford Maverick series
+ Diagnostics of malfunctions
+ Settings and routine maintenance
+ Engine
+ Cooling systems, heating and air conditioning
+ Power supply system and production of the fulfilled gases
- Systems of decrease in toxicity of the fulfilled gases
   System of ventilation of a case
   System of recirculation of the fulfilled gases (EGR) - models of 3.0 l
   Control system of quality of mix during a deseleration
   Control system of temperature of the soaked-up air
   System of catching of fuel evaporations (ECS)
+ Systems of electric equipment of the engine
+ Transmission
+ Coupling
+ Brake system
+ Forward and back bridges, running gear and steering
+ Body
+ Onboard electric equipment

System of ventilation of a case

Principle of action

The principle of functioning of system of the operated ventilation of a case (PCV) is presented on an accompanying illustration.
1 — the soaked-up air
2 — a cover of a mouth of the gulf of oil (tight)
3 — the PCV valve
4 — the measuring probe which is (hermetically put)
5 — crankcase evaporations

The crankcase evaporations including the gases which broke from combustion chambers bypassing piston rings in the structure come to the oil separator block located in a cover of a head of cylinders. Oil through drain openings comes back in the engine, and in an oil separator on a hose from the air cleaner clean air moves. Air mixes up with crankcase gases and via the valve of management of ventilation (PCV) comes to the inlet pipeline, and from there - to combustion chambers.

Most effectively the system functions at high turns of the engine when the small depth of depression in the inlet pipeline provides full opening of the PCV valve. Respectively, at the closed butterfly valves when in the inlet pipeline deep depression is formed, efficiency of ventilation of a case is minimum.

In strongly worn-out engine when level breaking in a case from combustion chambers of gases a temple, a part of crankcase evaporations gets back to the air cleaner regardless of the provision of butterfly valves.


The system is subject to regular service. Special attention should be paid for the listed below moments.


  1. Check passability and a condition of rubber hoses of system. Replace defective.
  2. Check a condition of sealing laying of a mouth of the gulf of motive oil and the measuring probe. Replace defective and/or suspicious a sealant.
  3. Check serviceability of functioning of the PCV valve.

Check of functioning of the PCV valve


  1. Disconnect PCV hose from a cover of a head of cylinders.
  2. Start the engine and leave it working at single turns.
    1. Press a finger to the open end of a hose (see an accompanying illustration). Depression has to be felt, otherwise passability of the PCV valve is broken. Clean the valve or replace it.

Location of the PCV valve on engines of 3.0 l is shown on an accompanying illustration.