Coolant change Audi A4

Parts and consumables:

• Coolant

Notes:

The coolant should only be changed if the engine cooling system is repaired, if the coolant was drained. Fluid replacement as part of maintenance is not provided. If the cylinder head, cylinder head gasket, radiator, heat exchanger or the engine itself were replaced during the repair, the coolant must be replaced in any case. This is necessary because the corrosion-protective components of the liquid during the running-in process are deposited on engine elements made of light alloys and thus form a long-term anti-corrosion protection. With used coolant, the corrosion protection components are already largely used up and cannot provide sufficient protection on new parts.

1 . To drain the coolant, remove the lower engine compartment cover, refer to  Removing and Installing the Engine Upper Cover/Under Engine Compartment Guard/Subframe .

Warning:

When opening the expansion tank on a hot engine, cover the expansion tank with a thick cloth to prevent hot fluid and steam from escaping. The cover may only be removed when the liquid temperature is below + 90°C.

2 . Open the cap of the expansion tank.

3 . Place a container under the radiator.

4 . 1.6, 1.8, 1.9, 2.5L engines and 2.0L ALT engine: Drain the coolant completely from the radiator. To do this, remove the retaining clip ( 1 ) of the coolant temperature sensor ( 2 ) from the lower hose and remove the sensor.

5 . Engine 1.9, 2.4, 3.0 l: if the radiator has a drain plug ( 2 ), turn it to the left and drain the coolant.

Note:

To direct the coolant to a specific place, put an auxiliary hose on the drain fitting. If there is no drain plug, drain the coolant through the temperature sensor hole ( 3 ). To do this, remove the side retaining clip and then remove the temperature sensor.

6 . All engines except 2.0L FSI (AWA), 4.2L (VVK) and 2.5L Diesel: Loosen the clamp and slide it all the way back. Remove the hose from the radiator ( arrow ) and drain the remaining fluid. Then put the hose back on immediately and secure it with the clamp.

7 . 2.0l AWA engine: open the drain plug ( 1 ) on the radiator pipe and drain the rest of the coolant. Then close it immediately. ( 2 ) - fastening nut, ( 3 ) - oil filter.

8 . Filling the system with coolant. Prepare coolant with 50% potable water and 50% VW/AUDI antifreeze/corrosion protection.

9 . Remove the lower engine cover, refer to  Removing and Installing the Upper Engine Cover/Under Engine Guard/Subframe .

10 . Lower the car onto its wheels.

11 . Fill the system with coolant through the expansion tank.

12 . Close expansion tank.

13 . Start the engine and set it to 2,000 rpm for about 3 minutes. Let the engine idle long enough to warm up the lower radiator hose.

Warning:

When opening the expansion tank on a hot engine, cover the expansion tank with a thick cloth to prevent hot fluid and steam from escaping. The cover may only be removed when the liquid temperature is below + 90°C.

14 . Check the coolant level and, if necessary, top up to the MAX mark.

15 . On a warm engine, the fluid level should be at the MAX mark, on a cold engine between the MAX and MIN marks.

16 . Stop the engine.

The article is missing:

• High-quality repair photos

Source:  http://audi-a4-2000manual.narod.ru/audi-984-10.m_id-83.m_id2-84.html