Audi A4, S4

since 2000 release

Repair and operation of the car

Check of functioning of the cooling system and frost resistance of cooling liquid

Address also to materials of the Section Check of a State and Replacement of Hoses of a Motive Compartment, localization of leaks.

PERFORMANCE ORDER

Many serious violations in operation of the engine are connected with malfunctions of the cooling system. If the car is equipped with automatic transmission, its functioning and service life are also directly connected with operation of the cooling system. Check of the cooling system has to be made at the cold engine therefore it is better to be engaged in it before a trip, the first for the present day, or not earlier than in three hours after switching off of the engine. Slowly, being careful in case the engine yet not absolutely cooled down, uncover a broad tank. Carefully wash out it from within and outside clear water. Check sealing laying of a cover. Low level of cooling liquid can be a consequence of the wrong navorachivaniye of a cover. Also wash out a jellied mouth. Existence of traces of corrosion in a jellied mouth means that liquid should be replaced. Liquid in a radiator has to be rather pure and transparent. If it has brownish color, devastate system and fill in in it new liquid Carefully check radiator hoses, and also heater hoses which have smaller diameter. Check cooling system hoses on all length, making replacement of any burst, blown up or worn-out hose. It is easier to find cracks if to squeeze a hose a hand. Pay special attention to the collars holding hoses on cooling system components. These collars can cut or pierce hoses that will lead to liquid leak. Make sure of reliability of fastening of all hose connections. Leak of liquid is usually shown in the form of white or rusty color of deposits in the field of sealing violation. If on your car collars of wire type are used, it is possible, there is a sense to replace them with collars of screw type. By means of compressed air or a soft brush clear forward part of a radiator (and also the air conditioner condenser where it is available). Remove all insects, the leaves and other foreign subjects which got on radiator edges. Be very careful not to injure an edge and not to cut about them fingers. If liquid level constantly falls, and you did not find any leaks, it is necessary to make check by pressure of a cover of a radiator and all cooling system.

Noticeable leak of cooling liquid and/or availability of oil in liquid, and also white cloudlets in the fulfilled gases indicate existence of defect in sealing laying of a head of cylinders.

Check of frost resistance of cooling liquid

Before a winter season it is necessary to check surely concentration of antifreeze in cooling liquid, especially if in system clear water was in use filled in.

You will need the special areometer with graduation of frost resistance of antifreeze.

Check

PERFORMANCE ORDER

Slightly warm up the engine so that the top hose of a radiator heated up. At measurement of concentration of antifreeze temperature of liquid has to make about +20 °C. At the hot engine the stopper of a broad tank should be opened carefully. There is a danger of a burn! It is necessary to put a rag on a stopper. Open a stopper only at a temperature of liquid no more than + 90 °C. Carefully turn off a stopper of a broad tank. Gather liquid by means of an areometer pear. The concentration of antifreeze providing protection of system up to the temperature of -25 °C at especially frigid climate is usually sufficient to –35 °C.

Removal of liquid

Antifreeze addition

Address to materials of Specifications.

In need of protection of the engine up to the temperature of -25 °C concentration of antifreeze in cooling liquid has to make 40%. In need of protection up to the temperature of -35 °C concentration of antifreeze has to make 50%.

If higher extent of protection against freezing is required, it is possible to increase the level of concentration of antifreeze to 60%. Such concentration will provide protection to –40 °C.

If concentration increases to higher level, extent of protection of the engine starts going down and, besides, heat-removing properties of cooling liquid worsen.

Air traffic jams

If after liquid replacement the engine overheats, the reason, most likely, available air traffic jams in system. These traffic jams do not allow liquid to circulate on all system. They appear as a result of too hasty gas station of system.

If you consider that in system there are air traffic jams, first of all try to squeeze all visible hoses in turn. You at once define, the hose is filled with liquid or air. As a rule, all air traffic jams disappear after the first (after liquid replacement) start of the engine.

At the working heated-up engine include a heater and its fan. Warm air has to come to salon in enough. If temperature of the given air low, the reason, perhaps, is an air stopper.

Consequences of emergence of air traffic jams in system can be very serious (not simply decrease in overall performance of a heater). The big stopper can stop circulation of liquid in the engine. To make sure of lack of traffic jams in the engine, touch the top hose of a radiator at the working engine — it has to be hot. If the hose cold, it testifies to existence of an air stopper in the engine or to the faulty thermostat.

If you could not get rid of air traffic jams, allow the engine to cool down completely, uncover a broad tank, try to squeeze hoses of system. If it did not help, merge all cooling liquid in the pure container and again fill system with the same liquid, following the recommendations provided above.