Engine cooling system (Audi A4 B8)

Caution! Risk of burns from hot steam and hot coolant. When the engine is warm, the cooling system is under excess pressure. To relieve excess pressure, first close the expansion tank cap. tank with a rag and carefully open it. When the engine is warm, the cooling system is under pressure. If necessary, relieve pressure before performing repair work. Secure all hose connections with hose clamps of the appropriate series. For installation of spring clamps, it is recommended to use the hose clamp pliers "VAG 1921" or the hose clamp pliers "VAS 6340". Gaskets and seals. the rings need to be replaced. Arrows applied to the ends of the tubes and hoses of the system. cooling, must be located opposite each other.

Coolant hose connection diagram

Cars without independent heater

Blue = large coolant circuit. Red = small coolant circuit. Brown = heating circuit.

Car with independent heater

Draining and filling the coolant

Open the expansion lid. tank. Remove the front sound insulation. Place a service tray under the engine. Unscrew the drain plug "1" and drain the coolant. Ignore "Pos. 2".

Refueling

Note: The cooling system is filled with a coolant solution and coolant additives for the entire year. Only coolant additives specified in the Electronic Parts Catalog should be used. Other additives can significantly reduce the anti-corrosion effect. The resulting damage may lead to coolant leakage and, as a result, to serious engine damage. Coolant with the correct mixture ratio prevents frost damage. formation of corrosion and limescale. In addition, they increase the boiling point. Therefore, an anti-corrosion concentrate that prevents freezing and corrosion must be used in the cooling system throughout the year. Particularly in countries with tropical climates, the coolant's higher boiling point ensures reliable engine operation under high loads. It is necessary to ensure that the coolant freezes at approximately -25°C (in countries with an arctic climate, approximately -35°C). Do not reduce the coolant additive content by adding water, even during warm weather or when operating in countries with a warm climate. The additive content should be at least 40%. If climatic conditions require a decrease in the freezing point of the coolant, the additive content can be increased, but not more than 60% (the freezing point in this case will be approximately -40°C). If this limit is exceeded, the freezing point of the coolant will increase again, and, in addition, the efficiency of the system will decrease. cooling. Use only clean drinking water to mix coolant. When replacing a radiator, heater heat exchanger, cylinder head, cylinder head gasket or cylinder block, reusing drained coolant is prohibited. Contaminated coolant cannot be used further. To check the additive in the cooling system, use the T10007 refractometer.

Ratio of components in coolant

Additive (40%) and water (60%) to ensure a freezing temperature of -25°C. Additive (50%) and water (50%) to ensure frost resistance down to -40°C.

Close the drain plug "1". Fill the "VAS 6096" reservoir with 10 liters of coolant, pre-mixed in the correct proportions. Screw on the system tester adapter. cooling "VAG 1274/8" to the expansion tank. Install the device for filling the system. cooling "VAS 6096" on the adapter "VAG 1274/8". Place outlet hose "1" into a small container "2". The exhaust air will capture a small amount of coolant, which must be collected. Close taps "A" and "B" by turning them perpendicular to the direction of flow. Connect hose "3" to compressed air. Pressure: excess pressure 6 - 0 bar.



Open valve "B" by turning it in the direction of flow. A vacuum is created in the cooling system using an ejector pump; the indicator arrow should be in the green field. Open tap "A" briefly, turning it parallel to the direction of flow so that the hose of the tank of the device for filling the system. the "VAS 6096" cooling system is full of coolant. Close valve "A" again. Open valve "B" for 2 minutes. The ejector pump continues to create a vacuum in the cooling system; the indicator arrow should be in the green field. Close valve "B." The indicator needle should remain in the green field, indicating that the cooling system has sufficient vacuum for further refilling. If the arrow is below the green field, you should repeat the previous operations. When the vacuum decreases, check the system. cooling for leaks. Remove the compressed air hose. Open valve "A". Due to the vacuum, the fluid coming out of the tank of the system filling device will flow. cooling "VAS 6096" Coolant fills the system..





Remove the VAS 6096 filling device from the adapter "VAG 1274/8" on expansion. system tank. cooling. Put on the tube "VAG 1274/10" on the adapter "VAG 1274/8".



Unlock the clamps and remove the seal of the water drainage box "2", "Pos. 1, 3" and "arrow" do not take into account.



Unscrew the coolant hose going to the heater heat exchanger and pull it back so that the vent hole "arrow" in the coolant hose is not blocked by the connecting nipple. Fill the coolant until it begins to flow out of the coolant hose vent. Attach the coolant hose to the connecting fitting and secure it with a spring clamp. On a vehicle with independent heating, turn on the heater for approx. for 30 seconds.





Close the expansion lid. tank. Start the engine. Set the temperature to "HI" in all zones. Turn off the compressor by pressing the ECON button. Run the engine at 2000 rpm for 3 minutes. Let the engine idle until the two large coolant hoses on the radiator warm up. The engine should run at 2000 rpm for 2 minutes. Turn it off and let the engine cool. Install the front noise insulation screen. Check the coolant level. When the engine is cold, the coolant temperature should be at the "MAX" mark. If the engine is warm, the coolant level may be above the "MAX" mark.

The diagram of the installation of the coolant pipe and the coolant pump after switching off. engine "V51"

Removal and installation of the system pump. bleeding coolant after turning off the engine "V51"

Loosen the "arrow" hose clamps and remove the air duct hose. "Pos. 1" should not be taken into account.



For absorbing the leaking coolant, place a rag under the coolant tube. Clamp the coolant hoses "arrows" with hose clamps up to 25 mm "3094" and remove them. Disconnect the connector "2". Unscrew the bolt "1" and remove the after-run coolant pump "V51".

Installation

Installation in reverse order. Hose fittings, air tubes and hoses must be cleaned of oil and grease before installation. Secure all hose connections with hose clamps of the appropriate series. To secure the air duct hoses to the fittings, treat the threaded connections of the already used clamps with a rust remover. Check the coolant level.

Cooling system pump and thermostat

Sequence of tightening the bolts for fastening the system pump. cooling

Tighten the system pump bolts. cooling in sequence. "1...5" with a torque of 9 Nm.

Removal and installation the coolant temperature sensor "G62"

Cold engine. Open the expansion tank cover briefly. tank for relieving residual pressure in the cooling system. Loosen the "arrow" hose clamps and remove the air duct hose. "Pos. 1" should not be taken into account.



Disconnect plug connection "1" of the throttle control unit "J338". Unscrew the bolts "arrows" and remove the throttle control unit "J338".



Remove the intake manifold support by unscrewing nut "2" and bolt "1." Depending on the model, different "G62" coolant temperature sensors may be installed.



Plug-in design: Disconnect plug connection "1" of the coolant temperature sensor "G62". Place a rag underneath to absorb any leaking coolant. Remove the latches by pressing the "arrow" stoppers. Remove the coolant temperature sensor "G62" "pos. 2".



Bolted design: Disconnect plug connection "2" of coolant temperature sensor "G62". Loosen bolts "arrows" and remove mounting plate "1". Remove coolant temperature sensor "G62".

Installation

Installation in reverse order. Replace the seal. rings. To avoid coolant loss, immediately insert the new "G62" coolant temperature sensor into the hose. Hose fittings, air ducts, and hoses must be cleaned of oil and grease before installation. Secure all hose connections with hose clamps of the appropriate series. To ensure reliable fastening of the air duct hoses to the fittings, the threaded connections of the already used clamps should be treated with a rust remover. Install the intake manifold support. Install the throttle control module "J338". Check the coolant level.

Removal and installation the toothed belt of the system pump. cooling

Remove the small coolant pipe. Remove coolant hoses "1 and 2" and place them aside.



Unscrew the arrow bolts and remove the timing belt protective cover.



Risk of thread damage. The drive pinion bolt has a left-hand thread. Unscrew the bolt on the drive gear "1" of the system pump. cooling with a torque wrench and the T10360 attachment, using a vibration damper as a counter-ax. Remove drive gear "1" and toothed belt "2".

Installation

Installation in reverse order. Replace the drive pinion bolt. Replace gaskets and seals. o-rings. Take into account the installation. position of the toothed belt pulley. Install the small coolant pipe. Fill with coolant.

Replacing the drive shaft gasket of the system pump. cooling

Remove the small coolant pipe. Remove the timing belt of the water pump. cooling. Press screwdriver "1" into area "2" of shaft gasket "arrow B". Press out gasket "arrow A". Clean working and sealing parts. surfaces.



Lubricate the sealing surface of balance shaft "2" with transmission oil. Place gasket "1" on the balance shaft. Signature "Outer Side" (or "Outside") "the arrow" should be read from the outside.



The drive pinion bolt has a left-hand thread. Install the "T10353" mandrel onto the shaft seal "1" and press it into the cylinder block until it stops with bolt "2", while not distorting the shaft seal.



Install the toothed belt of the system pump. cooling. Install the small coolant pipe. Fill with coolant.

Removal and installation the coolant pump

Remove the small coolant pipe. Remove the timing belt of the water pump. cooling. Disconnect plug connection "1" of the throttle control unit "J338". Unscrew the bolts "arrows" and remove the throttle control unit "J338".



Disconnect plug connection "1" of coolant temperature sensor "G62". Ignore "Pos. 2" and arrows.



Remove the coolant hoses; to do this, lift clamps "1" and "2" and place the coolant hoses aside.



Unscrew bolts "1...5". Detach the coolant pump from the centering bolts and remove it from the oil radiator. "Arrow" should not be taken into account.

Installation

Installation in reverse order. Replace gaskets and seals. o-rings. Wet the seal. coolant rings "4". Check that both centering pins are inserted into the cylinder block; reinsert if necessary. Insert connecting element "2" into oil cooler "1". Fit the system pump. cooling "3" on the connecting part and centering pins in the cylinder block.



Tighten the coolant pump bolts. When installing a new system pump. remove the protective cap "arrow" from the cooling system. Install the toothed belt of the system pump. cooling. Install the throttle control module "J338". Install the small coolant pipe. Fill with coolant.

Removal and installation the thermostat

Drain the coolant. Remove the coolant pump. Unscrew the bolts "arrows" and remove the connecting nipple. Remove the thermostat.

Installation

Installation in reverse order. Replace gaskets and seals. o-rings. Clean the sealing surface under the seal. ring. Wet the sealing ring with coolant. Insert thermostat "4" into housing "5" of the system pump. cooling and slightly turn the "arrow" forward. Carefully install the "3" branch pipe. At the same time, insert the centering pin "2" into the guide "1".



Install the intake manifold support. Install air ducts with a nipple coupling. Fill with coolant.

Radiator fan

Connect the coolant hose with the coupling

Remove the old seal. ring "2" from coolant hose "3". New seal. moisten the ring with coolant concentrate and insert it into the coolant hose. Push the coolant hose onto the coolant tube "1" until it clicks into place. Press the coolant hose in again and pull the hose to ensure that the coupling is properly secured.

Removal and installation the fan together with the fan frame

The radiator and fan frame can only be removed and installed as an assembly. Remove sound insulation. Remove the front bumper trim and bumper. Remove the intercooler. Remove the right headlight. On vehicles with headlight washers, remove the right headlight washer nozzle. Disconnect connector "1" of the front passenger side airbag crash sensor "G284".



Unscrew bolts "1" and "2". Disconnect and remove the right headlight "arrow" mount.



Place a service tray under the engine. Unscrew the drain plug "1" and drain the coolant. Remove coolant hose "2" from the radiator by pressing the fastening clip.



Before starting work in the fan frame area, disconnect the plug connections. Remove the plug connection "1" of the radiator fan from the mount by moving the lock back "arrow" and pressing the stopper down.



Unscrew the bolts "1, 2, 3, 5". Remove cover "4" of the radiator frame and hang it on the radiator grille "arrow".



Unscrew the arrow bolts.



Remove the connecting fittings "1" and "2" from the radiator. to do this, release the clamp. Remove air duct "1" and intermediate flange "2".



Cars with multitronic gearbox: Install a device for pumping out and collecting oil under the disconnect point. Loosen the arrow bolts and disconnect the ATF lines from the radiator.



To prevent ATF oil leakage, tie the ATF lines to the side member. To prevent contamination from entering, close the disconnected lines and pipes on the intercooler with a clean plug from the plug kit for the VAS 6122 engine.

All

Unlock the fastening brackets "arrows A" and remove the air duct "1" on the left and right "arrow B".



Unlock both radiator mounting bolts on the right and left and pull them upwards "arrows".



Unscrew the bolts "1" on the left and right and remove the radiator console together with the radiator from the radiator frame "arrow". Lower the radiator slightly.



The second mechanic must unlock the fastening brackets "1" in the direction of "arrow A"; the first mechanic must lift the condenser "2" upwards out of the retainers on the radiator "arrows B". Tilt the condenser with the connected hoses forward. Remove the radiator.



Simultaneously press the fan frame fastening tabs "arrow" on the right and left and remove the fan frame from the radiator in an upward direction.

Installation

Installation in reverse order. Install the air duct on the intermediate flange of the air casing. filter. On vehicles with a multitronic transmission, attach the ATF lines. Install the intercooler. Install the front bumper cover and bumper. Connect the coolant hose to the coolant pipe using a connecting coupling. Top up the coolant. After replacing the radiator, the coolant should be replaced. On vehicles with a multitronic transmission, check the ATF level.

(The original material is located on the website audimanual.ru)