Audi A4

Since 1994 of release

Repair and car operation

The six-cylinder engine

The device of automatic preliminary heating of soaked up air is from the entrance party of the case of the air filter. Before it there is a problem поддерживания favorable temperature of air which is soaked up by the engine.

For this purpose there is a following reason: at cold weather the toplivno-air mix is sated more if soaked up air moves preliminary нагретым. The Same quantity of warm air occupies больший volume, than cold air. As the engine can soak up only certain quantity of air at the included preliminary heating arrives a bit less air – the mix becomes richer, the fuel expense raises. For trouble-free work of the engine it is necessary only at low temperatures.

Functioning

Заслонка preliminary heating of soaked up air it is regulated by the thermostat which completely opens giving of warm air at temperature–20 С. At rise in temperature заслонка it is slowly closed until at temperature +5 С it will not be closed completely.

Infringements in work

If preliminary heating of air functions unsatisfactorily it can lead to operational infringements.

In a cold season:

• Unstable idling after start of the cold engine at a warming up stage.
• Bad switching, the engine it is inclined to faults.

In a warm season:

• The lowered capacity, is not reached the maximum speed.
• The raised expense of fuel.

Check of preliminary heating of air

The six-cylinder engine