Important Audi Coolant Reminders
As an independent Audi service garage with over 22 years of hands-on experience, we know what fails on Audis and why. We feel that changing your fluids is one of the most important preventive maintenance routines. Yet, for many Audi owners, this seems to be one of the most neglected area of maintenance. Thoroughly flushing your fluids at the proper intervals can help your Audi reach 150,000 miles and beyond!
#1 Audi Coolant Change Intervals
Blauparts recommends changing 'long life' Audi coolant every 3 to 4 years. Why? The combination of chemical additives contained in coolant, responsible for retaining alkalinity and inhibiting corrosion within the engine's cooling system, over time become depleted. Similar to oil, Audi coolant eventually breaks down, becomes weak, and "gets dirty." For maximum corrosion protection and prolonged engine life, flushing Audi coolant every 3 to 4 years (40,000 – 50,000 miles) is imperative. Thoroughly flushing your Audi's coolant is most convenient when done during timing belt replacement.
#2 What Type Of Audi Coolant
Use ONLY Audi Vw G11, or G12 approved anti-phosphate, anti-amine, anti-phosphorous coolant! Do NOT use regular store bought coolant, which typically contains ethylene glycol and doesn't correspond with the specifications of an Audi cooling system. The specification or type of Audi coolant required for a particular model can be found stamped on the expansion tank (e.g. G11 or G12) as well as in the owners manual under the coolant section. It's also good to note the color of your coolant (e.g. pink or purple). See Audi Coolant Features section below for further Audi coolant information and specifications.
What happens if you don't use correct approved Audi coolant?
Inferior coolant has an adverse reaction within an Audi cooling system. Poor quality coolant contaminates the system and eats away at metal, rubber, and plastic components. Obvious external indicators are bulging coolant hoses and white calcified residue oozing from coolant hose clamp mating areas (See Image 2). Not so obvious is lime and scale deposits that begin to build-up in the radiator core, restricting coolant flow and causing the engine to run hotter (especially in summer and warmer climates). All of this eventually causes serious engine problems (i.e. water pump failure - See Image 1). If your coolant is green or brown in color, thoroughly flush your cooling system immediately! You'll notice similar warnings in your owners manual under the coolant section.
#3 Audi Coolant Concentration
Remember to check the concentration (pH) of your Audi coolant on a regular basis. It's especially important to maintain the correct Audi coolant concentration during winter to protect your system against freezing temperatures. If your coolant concentration is weak, change it. Over time, weak or contaminated coolant (incorrect pH) can cause serious engine problems (i.e. water pump failure, as mentioned above). It's also important to note that approved Audi coolant comes in concentrated form. You MUST dilute the coolant using DISTILLED water to a 50/50 concentration. DO NOT mix normal tap water with coolant. Tap water varies in pH, mineral, and chemical content and can adversely affect your new coolant and cooling system. See Important Coolant Draining Flushing Filling Info section below for more information.
Important Audi Coolant Draining Flushing Filling Info
Draining Audi Coolant
Do you want your Audi to reach 150,000 miles and beyond; or your new water pump to last 60,000 to 90,000 miles? Then, it is important to replicate the cooling system to a like new factory condition. Simply draining is not enough. Draining alone can leave as much as 30 to 50% of the old coolant in the engine block. Your cooling system should be free of any and all contaminants! You can not be lazy when it comes to coolant flushing and water pump replacement! Cutting corners now adds time, labor, and money later.
It's the installers responsibility to take the necessary time to thoroughly flush the cooling system. It has been noted that due to time constraints, inconvenience, and profit, many individuals, mechanics, and repair shops do not take the extra time needed to thoroughly flush the entire cooling system. Thoroughly flushing the coolant involves the engine block, radiator, heater core, and hoses.
Premature water pump failure (bearings and seals) can occur if you don't take the time to flush the entire cooling system and it's related components. Often when problems arise, such as a coolant leak, the new Audi water pump is blamed as the cause when in fact the opposite is true. It's usually because the installer neglected to follow this important step.
Flushing The Audi Cooling System
It is imperative that the Audi cooling system be thoroughly flushed of all accumulated silt and sediment buildup. All aftermarket cooling system additives, or stop leak products that may have been added to the cooling system (past or present) should be completely flushed! Thoroughly flushing the cooling system involves the engine block, radiator, heater core, and hoses.
Only use tap water to flush the entire cooling system. Do NOT use cooling system flush products. Many of these agents contain muriatic and/or other acids. Remnants of these acids left in the cooling system can cause your new Audi water pump to prematurely fail (see example images on related water pump replacement page).
Filling and Topping Off The Audi Cooling System
Use ONLY Audi Vw G11, or G12 approved anti-phosphate, anti-amine, anti-phosphorous coolant! Do NOT use regular store bought coolant, which typically contains ethylene glycol and doesn't correspond with the specifications of an Audi cooling system. It's also important to note that approved Audi coolant comes in a concentrated form. You MUST dilute the coolant using DISTILLED water to a 50/50 concentration. DO NOT mix normal tap water with coolant. Tap water varies in pH, mineral, and chemical content and depending on these factors can adversely affect your new coolant and the cooling system. Never fill or top off with full concentrate G11 or G12 Audi coolant. Your Audi coolant should never exceed a coolant ratio of 60%. If it's over 60%, an inefficient Audi cooling system will result, decreasing flow through the radiator along with poor heat transfer through the engine block.
Important Reminder: Make sure that your local quick lube or mechanic isn't adding or topping off your system with incorrect coolant. Mixing factory approved coolant with any other coolant will cause an adverse chemical reaction with the existing coolant and contaminates the cooling system, thus affecting the longevity of the Audi water pump. If your coolant is green or brown in color thoroughly flush your cooling system immediately! You'll notice similar warnings in your owners manual under the coolant section. Read the warnings on the antifreeze coolant bottle regarding improper use being harmful or fatal. Click here for our detailed page covering everything about Audi coolant / Audi antifreeze.
Back To Top
How To Flush Audi Coolant - Basic Overviews
Flushing your Audi's coolant is most easily done when replacing your timing belt.
Refer to the factory Bentley manual for Audi cooling system capacities and mixture ratios.
We recommend having an A.S.E. certified Audi mechanic change your Audi coolant. Always wear gloves and safety goggles when handling Audi fluids.
This is a basic overview of what is involved when flushing Audi coolant. It is not intended to replace the factory Bentley manual.
Please refer to the factory Bentley manual for detailed instructions.
How To Change Engine Coolant On An Audi 4 Cylinder (1997 - On) :
- When the engine has cooled down, remove the Audi coolant tank cap.
- Draining the Audi coolant from the 4cyl cooling system:
Remove the lower radiator drain plug from the lower front of the radiator (Audi A4, Vw Passat). Remove the passenger side lower radiator hose. Remove the outer Audi coolant hose that connects to the oil cooler. To drain the heater core you'll need to remove the hose on the coolant flange or transfer pipe located on the back side of the engine. This hose goes from the cylinder head to the heater core.
- After the system is done draining, put the Audi coolant tank cap back on. Carefully work off and remove the smallest hose that is connected to the top of the Audi coolant tank. Be careful, the tank nipple likes to crack and break off.
- With a blow gun and compressed air on low, carefully insert the blow nozzle into the small hose. Wearing safety goggles, carefully force the air out so that any Audi coolant that's still trapped in the cooling system is released.
- Reinstall the Audi coolant drain plug. Reinstall the coolant tank hose(s). Fill the Audi cooling system with distilled water. Start the car and air bleed the cooling system as outlined in the factory Bentley manual. Run the car until the cooling fan comes on.
- Repeat steps 1 through 5 until the water comes out clean.
- Verify that you have the correct anti-phosphate anti-amine G11 or G12 Audi coolant. If it's full concentrate, mix a 50/50 ratio per the Bentley manual. Fill your Audi cooling system with this 50/50 mixture. You MUST dilute the coolant using DISTILLED water to a 50/50 concentration. DO NOT mix normal tap water with coolant. Tap water varies in pH, mineral, and chemical content and depending on these factors can adversely affect your new coolant and the cooling system. Note: Some factory Audi coolants sold by dealers are already premixed and do not require further dilution.
- Run the 4cyl engine and check for any Audi coolant leaks.
- Top off the coolant tank to the fill line. Do not overfill.
- Using a permanent marker, write 'G11 or G12 Coolant Only' on the Audi coolant tank.
- Be environmentally responsible and dispose of your old Audi coolant properly.
How To Change Engine Coolant On An Audi 5 Cylinder:
- When the engine has cooled down, remove the Audi coolant tank cap.
- Draining the Audi coolant from the 5cyl cooling system:
Remove the lower radiator hose. Only about 75% of the Audi coolant will drain, the rest is in the engine block and heater core. To drain the heater core you'll need to remove the hose on the coolant flange or transfer pipe located on the back side of the engine. This hose goes from the cylinder head to the heater core. You can also drain the engine block by removing the thermostat housing or the small 6" hose adjacent from the thermostat housing. This hose connects to the steel tubing that runs along side the engine block to the back of the engine.
- Reinstall the hoses. Fill the Audi cooling system with distilled water. Start the car and air bleed the cooling system as outlined in the factory Bentley manual. Run the car until the cooling fan comes on.
- Repeat steps 2 through 3 until the water comes out clean.
- Verify that you have the correct anti-phosphate anti-amine G11 or G12 Audi coolant. If it's full concentrate, mix a 50/50 ratio per the Bentley manual. Fill your Audi cooling system with this 50/50 mixture. You MUST dilute the coolant using DISTILLED water to a 50/50 concentration. DO NOT mix normal tap water with coolant. Tap water varies in pH, mineral, and chemical content and depending on these factors can adversely affect your new coolant and the cooling system. Note: Some factory Audi coolants sold by dealers are already premixed and do not require further dilution.
- Run the 5cyl engine and check for any Audi coolant leaks.
- Top off the coolant tank to the fill line. Do not overfill.
- Using a permanent marker, write 'G11 or G12 Coolant Only' on the Audi coolant tank.
- Be environmentally responsible and dispose of your old Audi coolant properly.
How To Change Engine Coolant On An Audi V6:
- When the engine has cooled down, remove the Audi coolant tank cap.
- Draining the Audi coolant from the V6 cooling system:
There is a 8mm Allen drain plug on the back side of the subframe cross member offset to the drivers side. It is recessed about 1 inch into the casting of the engine block. You'll probably need a flash light to find it. To drain the heater core you'll need to remove the hose on the coolant flange or transfer pipe located on the back side of the engine. This hose goes from the cylinder head to the heater core.
- After the system is done draining, put the Audi coolant tank cap back on. Carefully work off and remove the smallest hose that is connected to the top of the Audi coolant tank. Be careful, the tank nipple likes to crack and break off.
- With a blow gun and compressed air on low, carefully insert the blow nozzle into the small hose. Wearing safety goggles, carefully force the air out so that any Audi coolant that's still trapped in the cooling system is released.
- Reinstall the Audi coolant drain plug. Reinstall the coolant tank hose(s). Fill the Audi cooling system with distilled water. Start the car and air bleed the cooling system as outlined in the factory Bentley manual. Run the car until the cooling fan comes on.
- Repeat steps 1 through 5 until the water comes out clean.
- Verify that you have the correct anti-phosphate anti-amine G11 or G12 Audi coolant. If it's full concentrate, mix a 50/50 ratio per the Bentley manual. Fill your Audi cooling system with this 50/50 mixture. You MUST dilute the coolant using DISTILLED water to a 50/50 concentration. DO NOT mix normal tap water with coolant. Tap water varies in pH, mineral, and chemical content and depending on these factors can adversely affect your new coolant and the cooling system. Note: Some factory Audi coolants sold by dealers are already premixed and do not require further dilution.
- Run the V6 engine and check for any Audi coolant leaks.
- Top off the coolant tank to the fill line. Do not overfill.
- Using a permanent marker, write 'G11 or G12 Coolant Only' on the Audi coolant tank.
- Be environmentally responsible and dispose of your old Audi coolant properly.
How To Change Engine Coolant On An Audi V8:
- When the engine has cooled down, remove the Audi coolant tank cap.
- Draining the Audi coolant from the V8 cooling system:
There are 2 drain plugs. One on the drivers side and one on the passenger side of the oil pan. To drain the Audi coolant from the radiator, remove the lower passenger side radiator hose.
- After the system is done draining, put the Audi coolant tank cap back on. Carefully work off and remove the smallest hose that is connected to the top of the Audi coolant tank. Be careful, the tank nipple likes to crack and break off.
- With a blow gun and compressed air on low, carefully insert the blow nozzle into the small hose. Wearing safety goggles, carefully force the air out so that any Audi coolant that's still trapped in the cooling system is released.
- Reinstall the Audi coolant drain plugs. Reinstall the coolant tank hose(s). Fill the Audi cooling system with distilled water. Start the car and air bleed the cooling system as outlined in the factory Bentley manual. Run the car until the cooling fan comes on.
- Repeat steps 1 through 5 until the water comes out clean.
- Verify that you have the correct anti-phosphate anti-amine G11 or G12 Audi coolant. If it's full concentrate, mix a 50/50 ratio per the Bentley manual. Fill your Audi cooling system with this 50/50 mixture. You MUST dilute the coolant using DISTILLED water to a 50/50 concentration. DO NOT mix normal tap water with coolant. Tap water varies in pH, mineral, and chemical content and depending on these factors can adversely affect your new coolant and the cooling system. Note: Some factory Audi coolants sold by dealers are already premixed and do not require further dilution.
- Run the V8 engine and check for any Audi coolant leaks.
- Top off the coolant tank to the fill line. Do not overfill.
- Using a permanent marker, write 'G11 or G12 coolant Only' on the Audi coolant tank.
- Be environmentally responsible and dispose of your old Audi coolant properly.
Back To Top