A coolant leak can happen in any car. It is when your coolant leaks from the coolant reservoir, generally straight through the engine and onto whatever surface you’re parked or driving on. You often discover this when your Audi has a low coolant light go off or your engine begins to overheat. You may also discover a coolant leak by seeing coolant pool up under your car.
Can you drive with a coolant leak?
It is generally not a good idea to drive with a coolant leak. If your Audi becomes low on coolant it can overheat, causing damage to the engine. Overheating your engine is one of the easiest ways to cause long-term damage to an engine, so it is important to get a coolant leak fixed as soon as possible.
Where do coolant leaks occur?
Coolant leaks are either internal or external. Internal coolant leaks are dangerous because it is not possible to see where the leak is coming from. You also cannot see a puddle outside of the car, making it harder to detect. External leaks are easy to diagnose because the coolant often escapes the car and creates a puddle.
Common sources of a coolant leak are:
The Radiator
The radiator is pressurized, but is exposed to the stones, vibrations, shocks, and airflow that enter the front of the vehicle. Because of this, the metal on the radiator can rust or suffer metal fatigue, causing a coolant leak.
The Radiator Cap
This is the cap on top of the radiator or its expansion tank where you can check your car’s coolant level. It should be sealed to maintain pressure for the cooling system. However, if it deteriorates, the cooling system will lose its pressure, which can cause a leak.
The Radiator and Heater Hoses
Hoses carry the coolant from the engine and heater core to the radiator. When the hoses get older, they can crack or develop holes which cause the hoses to leak coolant. This is particularly common where the hose bends or where they attach to the radiator, engine, or heater core.
The Expansion Tank
The expansion tank holds extra coolant. It is connected to the radiator with a hose. The tank can leak if the container is cracked, the cap is loose, or a hose has broken or developed a hole.
The Water Pump
The water pump circulates the coolant, and if it breaks, it can cause the car to overheat quickly. If the seal fails, the gasket does not work, or if there is external damage, it can cause a coolant leak.
The Thermostat
The thermostat regulates temperature. A coolant leak can result if it cracks or the gasket fails.
The Heater Core
The heater core provides heat to the inside of the car. Any damage to the core or the hoses it is connected to can cause a coolant leak.
The Intake Manifold Gasket
The intake manifold gasket provides air and fuel to the cylinders in the engine. This gasket can fail and leak coolant.
The Head Gasket
The head gasket provides a seal between the engine block and the cylinder heads. If it fails where it is exposed to the exterior of your car’s engine, you may be able to locate the leak. However, this often happens internally, so you may not be able to see the leak or coolant. A combination of oil and coolant is a sign of potential head gasket failure.
Where do coolant leaks most often occur in Audis?
Coolant leaks in Audis most often occur where the hose connects to the engine. The hose can develop porous, hairline cracks where the connect to the engine or reservoir. These cracks can be inside of the hose so they are difficult to troubleshoot. The best way to fix the leak is to get the hose replaced. It is best to get all of the hoses replaced if you go in to get one replaced that has deteriorated from age.
How Escondido German Auto Can Help
Our automotive specialists at 
Escondido German Auto can help. We specialize in German automobile service and repairs, specifically, Audi, BMW, Mercedes-Benz, MINI, Porsche, Sprinter, and Volkswagen, at our location convenient to Escondido, Rancho Bernardo, and Valley Center, CA. Coolant leaks are not unique to Audis, but we know your car deserves the best care. Our trained mechanics have decades of experience with Audi and other German luxury automobiles. Our experts at Escondido German Auto provide high-quality services and repairs without the hassles and high costs of a dealership.