Figure 42. Air filter and thermostat of the VAZ-2108 car:
1 - cold air intake; 2 - corrugated hose of the heated air intake; 3 - thermostat; 4 - body; 5 - filter element; 6 - cover.
The filter consists of a housing 4, a cover 6, a filter element 5, a cold air intake 1 and a warm air intake with a corrugated hose 2. The housing and cover are stamped from 0.8 mm thick sheet steel and painted with a black primer. The cover is attached to the housing with four spring latches and, in the center, additionally, with a nut on the bracket stud. The bracket is welded to the air filter housing. The tightness of the housing-to-cover connection is ensured by a polyurethane foam sealing gasket glued to the cover.
The filter cover must be installed in a strictly defined manner to reduce intake noise. The arrows stamped on the cover and the intake pipe must point towards each other.
Dry filter element 5 is the same as the one in the car VAZ-2121. The filtering part of the element has the form of an accordion, which is made of special filter cardboard and is filled together with the internal and external perforated tin shells into elastic covers made of self-hardening sealant, due to which, when installing the cover 6 of the air filter, the filter element 5 is reliably sealed with the body and the cover. To increase the dust capacity of the filter element, a pre-cleaner made of synthetic cotton wool is put on the external perforated shell.
It is not recommended to clean or restore the filter element, as this may damage the filter cardboard.
The air filter housing has an intake pipe through which air is sucked in. A plastic thermostat 3 with a cold air intake 1 installed on it is attached to the intake pipe with a tightening bolt. To reduce intake noise, the air intake is made of polyurethane foam.
On VAZ-21083, 2109 and 21093 vehicles, air intake 2 (figure 43) with air duct 3 cold air have a different design, different from the VAZ-2108. Air intake 2 is made of polypropylene and is fastened with screws to the front cross member of the body above the radiator of the cooling system. Air intake pipe 2 is connected by a corrugated polypropylene air duct 3 to the pipe of the thermostat 4. Cold air in this case does not come from the engine compartment, as in VAZ-2108 cars, but is sucked directly from under the lining of the engine radiator.
Figure 43. Air filter and thermostat of the VAZ-2109 car:
1 - heated air intake; 2 - cold air intake; 3 - air duct; 4 - thermostat; 5 - lid; 6 - gasket; 7 - filter element; 8 - body; 9 - mounting plate; 10 - air filter gasket.
Thermoregulator
Thermostat 4 (see figure 43) allows maintaining the temperature of the air entering the air filter within 25...35°C when the engine is warm.
The thermostat consists of a plastic disassemblable housing, a hinged damper, a composite rod and a thermal power element. The lower arm of the damper is connected by a hinge to the composite rod. The other end of the rod is pressed against the pusher of the thermal power element. The thermal power element is screwed with a rod into the plug of the thermostat housing. The heat-sensitive filler of the thermal power element expands when heated and acts on the pusher and rod, slightly opening the thermostat damper. The thermal power element is washed by the suction air and, at a temperature above plus 35°C, closes the warm air intake pipe with the damper, opening access for cold air. Conversely, at a temperature below plus 25°C, the damper closes the cold air intake pipe. In this case, the air will be sucked in heated from the exhaust manifold area of the exhaust system. When the air temperature is within 25...35°C, the damper is in intermediate positions and maintains the optimal temperature of the air entering the engine.