Audi 80/90/Coupe

since 1986-1991 release

Repair and operation of the car

All laying and consolidations are subject to replacement. Without fail fix hoses by collars.

Check the cooling system by means of the equipment Snap On SVT 362 and 4467.

If in oil a significant amount of metal shaving is found, then it is necessary to clean oil channels and to replace an oil filter.

All specified details can be removed and established without dismantle of the engine from the car.

Replacement of cooling liquid

The cooling system of the Audi cars of all models are filled at manufacturer with mix of water and antifreeze (G 11) with anticorrosive additives. Such cooling mix can be used all the year round.

The antifreeze which is not containing phosphates increases frost resistance, prevents corrosion and scaling, and, besides, raises a boiling point. Increase in a boiling point of cooling liquid improves operational parameters during the work with the maximum load, especially in tropical conditions.

When replacing cooling liquid in the Audi cars of all models irrespective of a year of release it is necessary to fill the cooling system with the ZVW237 102 antifreeze which is not containing phosphates.

When the engine is heated-up up to the normal working temperature, the level of cooling liquid in a broad tank has to be a little higher than maximum tag. When the engine cold, the level of cooling liquid in a broad tank has to be between tags of minimum and maximum.

It is forbidden to touch fan blades. The fan can spontaneously turn on at operation of a timer. In a heated motor compartment the cycle of turning on of the fan can repeatedly be repeated after an engine stop.

Modern cars are equipped with system of automatic start of the fan for cooling of a fuel pipe and injectors after an engine stop that facilitates the subsequent launch of the hot engine.

Principle of work of system

If temperature in space of a motor compartment after a stop of the engine is above 110 °C, then the thermoswitch includes a timer which in turn turns on the fan.

When temperature becomes below 103 °C, the relay switches-off the fan. Such cycle can repeatedly be repeated, for 10–12 min.

System details

Thermoswitch

It is mounted on an arm which fastens to a block head between the 1st and the 2nd cylinders (from an injector).

Timer

After operation of a thermoswitch, a timer turns on the fan on the first speed of rotation for 10–12 min. after an engine stop.

Fan thermoswitch – operation thresholds

Switch	Temperature of inclusion / switching off
	incl.	off.
Three-chambered, provides connection with a positive pole of the battery, inclusion of the first speed of rotation	92 – 97 °C	84 – 91 °C
Second speed of rotation of the fan	99 – 105 °C	91 – 98 °C

Search of malfunctions

Timer

It is mounted on an auxiliary guard under the dashboard on the left side.

Turn the ignition key in position of ON and OFF.

Connect a thermoswitch wire to the mass of the car.

The fan has to turn on at the first speed of rotation.

Test has to be executed within 10–12 minutes after an engine stop as the timer works during this period.

Position of ON – closes contact on the weight when temperature in a motor compartment is above 110 °C.

Position of OFF – contacts are opened when temperature in a motor compartment is below 103 °C.

Electrical wiring

By search of malfunctions of an electric chain you watch subsection 14.3.2.

Calibrating of the areometer for antifreeze

For ensuring accuracy of measurements, it is necessary to check calibrating of the areometer periodically.

In a small vessel mix antifreeze and water in the ratio 1:1.

The indication of the areometer has to be -35 °C. If the indication differs, then put the tag corresponding of -35 °C.

Fan thermoswitch – operation thresholds

Switch	Temperature of inclusion / switching off
	incl.	off.
Three-chambered, provides connection with a positive pole of the battery, inclusion of the first speed of rotation	92 – 97 °C	84 – 91 °C
Second speed of rotation of the fan	99 – 105 °C	91 – 98 °C

Calibrating of the areometer for antifreeze

For ensuring accuracy of measurements it is necessary to check calibrating of the areometer periodically.

in a small vessel mix antifreeze and water in the ratio 1:1

the indication of the areometer has to be -35 °

if the indication differs, then put the tag corresponding -35 °

Replacement of cooling liquid

The antifreeze which is not containing phosphates increases frost resistance, prevents corrosion and scaling, and, besides, raises a boiling point. Increase in a boiling point of cooling liquid improves operational parameters during the work with the maximum load, especially in tropical conditions.

When replacing cooling liquid in the Audi cars of all models, irrespective of a year of release, it is necessary to fill the cooling system with the ZVW237 102 antifreeze which is not containing phosphates.

The recommended mixes

Gas station

PERFORMANCE ORDER

1) establish into place and fix hoses 2) unscrew the screw of the ventilating valve (it is specified by an arrow) 3) fill a broad tank of cooling liquid to maximum tag 4) when cooling liquid begins to be poured, wrap the screw of the ventilating valve 5) close a tank a stopper 6) start the engine and warm up it before the first operation of the fan

Cooling system components (Coupet's model)

1. Consolidation 2. Radiator guard, top section 3. 10 N. of m. 4. Rubber-metal plug, 10 N. of m. 5. Fan 6. Radiator guard, right section 7. 20 N. of m. 8. Radiator 9. Sealing washer 10. Thermoswitch, 25 N. of m.

11. Stopper of a broad tank check: by means of VAG 1274 and VAG 1274/1A adaptation control pressure is from 1,2 to 1,5 atm 12. Broad tank 13. Radiator casing 14. To a head of the block of cylinders 15. To the thermostat 16. To an additional radiator

Check leaks in the cooling system by means of VAG 1274 and VAG 1274/1A adaptation.

Replace laying and consolidations. Fix all hoses by collars with fixing by the screw.

The antifreeze which is not containing phosphates increases frost resistance, prevents corrosion and scaling, and, besides, raises a boiling point. Increase in a boiling point of cooling liquid improves operational indicators of the engine during the work with the maximum load, especially in tropical conditions.

When replacing cooling liquid, or at restoration of level, it is necessary to fill the cooling system with the ZVW237 102 antifreeze which is not containing phosphates. It belongs to all models of the Audi cars, irrespective of a year of release.

The recommended mixes

Gas station

PERFORMANCE ORDER

1) open the ventilating valve (it is specified by an arrow) 2) fill in cooling liquid to maximum tag on a broad tank 3) you monitor intake of liquid via the ventilating valve as soon as liquid begins to be poured, close the valve 4) close a tank a stopper 5) start the engine and warm up it before the first operation of the fan 6) check the level of cooling liquid, if necessary restore

When the engine is heated-up up to the normal working temperature, the level of cooling liquid in a broad tank has to be a little higher than maximum tag. When the engine cold, the level of cooling liquid in a broad tank has to be between tags of minimum and maximum.