Vehicle cooling system Audi 100 C4, petrol

This is how cooling occurs
When the engine is running, the water pump constantly pumps coolant through the engine's many cooling channels and removes the heat generated in the cylinders...

Checking the coolant level
Constantly checking Although there is a coolant temperature/level indicator, you should not rely solely on it and should check the coolant level in the...

Adding coolant
A noticeable loss of coolant is a sign of a malfunction or breakage. Coolant is not consumed, and in a closed cooling system it cannot evaporate. A small...

Frost resistance test
To check the frost resistance of the coolant, you need a special device - a hydrometer. It measures the specific gravity of the liquid. Due to different means...

Checking the cooling system for leaks
Defective areas in the cooling system are easiest to identify when the engine is hot and, accordingly, the operating pressure in the cooling system. But in...

Radiator
The radiator is equipped with so-called plastic tanks. They are located on the right and left of the radiator in models with 4- and 6-cylinder engines, and at...

Threaded cap of expansion tank
Under conditions of high pressure in the cooling system, the expansion tank threaded cap plays an important role: When the lid is closed, its sealing surface...

Thermostat
In simple terms, the thermostat determines whether the coolant will circulate or not. That is, it determines whether the coolant should flow through the small...

List of faults
Thermostat Note: If the engine boils on the road due to a faulty thermostat, either a tow truck or removing the thermostat on the spot can help. If you decide...

Water pump
In order for the coolant to circulate in the cooling system, it is pumped by a water pump. It is driven in different ways, depending on the type of engine: On...

Cooling system fan
The Audi 100 is equipped with different cooling system fans depending on the engine type. Models with 4- and 6-cylinder engines have an electrically driven fan...

Cooling system fan malfunctions
Besides the jammed thermostat and broken V-belt (only on models with 4-cylinder engine) a faulty cooling fan can cause the coolant temperature to be too high,...

Hydraulic fan
5-cylinder engines only The hydraulic fan creates a continuous air flow through the radiator grille when the flow from the main electric fan is insufficient....

List of faults in the cooling system

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100(C4, 1990-1994)

100(C4, 1990-1994, petrol)

100(C3, 1982-1990)

100(C3, 1982-1990, petrol)

100(C3, 1982-1990, diesel)