Pic. 42. Air filter and thermostat car VAZ-2108:
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 body 4, a cover 6, a filter element 5, a cold air inlet 1 and a warm air inlet with a corrugated hose 2. The body and cover are stamped from 0.8 mm thick sheet steel and painted with a black primer. The cover is attached to the body 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 interface between the body and the cover is ensured by a sealing gasket made of polyurethane foam glued to the cover.
The filter cover must be installed in a specific way to reduce intake noise. The arrows stamped on the cover and the inlet must point towards each other.
Dry filter element 5 is used the same as that of the car VAZ-2121. The filtering part of the element has the form of an accordion, which is made of a special filter cardboard and is filled together with the inner and outer perforated tin shells into elastic covers made of self-hardening sealant, due to which, when the cover 6 of the air filter is installed, the filter element 5 is reliably sealed with the body and cover. To increase the dust capacity of the filter element, a pre-cleaner made of synthetic wool is put on the outer perforated shell.
Cleaning or reconditioning of the filter element is not recommended as the filter paper may be damaged.
The air filter housing has an inlet pipe through which air is sucked in. A plastic thermostat 3 with an air intake 1 of cold air mounted on it is attached to the intake pipe with a coupling bolt. To reduce intake noise, the air intake is made of polyurethane foam.
On VAZ-21083, 2109 and 21093 cars, air intake 2 (pic. 43) with an air duct 3 of cold air have a different design than the VAZ-2108. The air intake 2 is made of polypropylene and is screwed to the front cross member of the front end of the body above the radiator of the cooling system. The air intake pipe 2 is connected by a corrugated polypropylene air duct 3 to the thermostat pipe 4. In this case, cold air does not come from the engine compartment, as in VAZ-2108 cars, but is sucked directly from under the engine radiator lining.
Pic. 43. Air filter and thermostat car VAZ-2109:
1 - heated air intake; 2 - cold air intake; 3 - air duct; 4 - thermostat; 5 - cover; 6 - gasket; 7 - filter element; 8 - body; 9 - mounting plate; 10 - air filter gasket.
Thermostat
Temperature controller 4 (see fig. 43) allows, when the engine is warm, to maintain the temperature of the air entering the air filter within 25... 35°C.
The temperature regulator consists of a plastic collapsible body, a hinged damper, a composite rod and a thermal force element. The lower arm of the damper is pivotally connected to the composite rod. The second end of the rod is pressed against the pusher of the thermo-force element. The thermopower element is screwed into the cork of the thermostat housing with a rod. When heated, the temperature-sensitive filler of the thermo-force element expands and acts on the pusher and rod, slightly opening the thermostatic valve. The thermal force element is washed by the suction air and at a temperature above plus 35°C closes the warm air intake pipe with a damper, opening access to cold air. On the contrary, at temperatures below plus 25°C, the damper closes the cold air inlet. At the same time, air will be sucked in heated from the area of the exhaust manifold of the exhaust system. When the air temperature is within 25...35°C, the damper is in intermediate positions and maintains the optimum temperature of the air entering the engine.