Audi Check Coolant / Add Antifreeze DIY Guide

Audi Check Coolant / Add Antifreeze DIY Guide

Last Updated on Thursday Mar 08, 2018

In this guide, you will find instructions on how to check engine coolant on Audi vehicles and add coolant if the level is low. These instructions apply to Audi A3, S3, RS3, A4, S4, A5, S5, A6, S6, A7, S7, RS7, A8, S8, Q3, Q5, SQ5, Q7, TT, R8. Rember to only remove the coolant cap or add coolant after the engine has cooled down. Do not open the radiator or coolant expansion cap when the engine is still hot.


  • Engine Overheating,
  • Temperature gauge in the HIGH range,
  • Check Coolant Warning,
  • Low Engine Coolant Message

What you will need:


Step 1 - Open Hood

Park your Audi on a level surface. Wait for the engine to cool down. Once your engine has cooled down you can proceed by opening the hood. Pull the lever until you hear the hood pop open. Next, you need to release the hood safety latch at the front of your Audi.

Step 2 - Locate Coolant Reservoir

How to check coolant  Audi 8P EV B6 B6 B7 B8 C4 C5 C8 C7 D2 D3 D4

Next, you locate the coolant reservoir (tank) on your particular Audi. The engine coolant reservoir is shown as item 7 in the pictures above. On a the coolant reservoir is located on the driver or passenger side of the engine.

Step 3 - Check Coolant Level

check low coolant level A3, S3, RS3, A4, S4, A5, S5, A6, S6, A7, S7, RS7, A8, S8, Q3, Q5, SQ5, Q7, TT, R8

Remove cap. Look at the coolant reservoir tank and note the low and high level.

audi max and min coolant level


audi coolant reservoir

Coolant expansion tank on Audi A4 located on the passenger side of the engine.

If the level is below the minimum mark you will need to add coolant or your Audi engine will overheat.

Step 4 - Add Coolant / Antifreeze

Add engine coolant/antifreeze. Only add coolant type recommended by Audi. In case of an emergency, it is ok to use aftermarket coolant. It is recommended that the system is flushed and filled with the recommended coolant when possible.


  1. Do not remove the radiator or the coolant reservoir cap when the engine is hot. Let the engine cool down or you risk getting burned by the coolant. Allow the engine to cool down before you remove the cap. Hot coolant may blow out of the radiator causing serious injuries or burns. Use a thick towel to place on top of the cap. Press the cap down and turn it slowly counterclockwise. Allow pressure to release from the system for a couple of seconds before you remove the cap. If the engine is still hot, the system may still be under pressure.
  2. Always use the correct coolant type. Generally, you need to mix 50% full strength antifreeze with 50% water but it is recommended to follow your manufacturer's percentages for mixing coolant and water.
  3. Do not only use ONLY water in the cooling system, especially in a car that is overheating. If you are not sure what type of coolant to use, look it up in your owner's manual. If that is not available, use a coolant that will mix with any color.
  4. Add coolant until it is filled to the recommended level. Tighten the cap. Visually inspect the cooling system and the hoses for any visible leaks. If you notice any damaged hoses, then replace them as soon as possible.
  5. Antifreeze with corrosion inhibitors may contain ethylene glycol which is flammable. Avoid spilling antifreeze on a hot engine to avoid causing a fire. 
  6. Antifreeze and anti-corrosion agents can be hazardous to your health. Keep your coolant container in a safe place and away from the reach of children.
  7. Coolant in your vehicle not only cools down the engine and prevents it from overheating. It also protects it from freezing in the winter.