"coolant temperature to high let engine run" message

Audi Coolant Temperature too High [Causes & How to Fix]

Without any doubt, Audis are one of the most beautiful vehicles, from my experience they are easy to drive, have luxurious interiors, and for some models easy to work on.

One of the most common problems, Audi owners have reported is the “Coolant Temperature too High” warning message.

Fortunately, I had a few Audis come to my workshop with the same problem and in this article, I am going to discuss the main causes and how to fix and reset the “Coolant Temperature too high” message. let’s get to it.

What Does ” Coolant Temperature Too High” Mean on an Audi?

The fault Coolant temperature too high message coming on your Audi’s infotainment system simply means the vehicle has detected that the temperature of the coolant fluid is too high.

The coolant reservoir has a sensor attached to it, also known as a “Coolant Temperature Sensor” which is responsible for sensing the temperature of coolant fluid and sending this information to the vehicle’s computer.

When the coolant temperature sensor detects that the coolant is too high, it sends a signal to your Audi’s infotainment system which displays a warning message on your screen.

Audi Coolant Temperature Too High Main Causes and Fix

Technically there are a lot of things that can cause this fault message to come on, but from working with a lot of Audi’s there are 3 things that seem to cause it more often than not.

1. Faulty Coolant Temperature Sensor:

The coolant temp sensor is responsible for sending a signal to the vehicle’s computer letting it know how hot or cold the coolant is.

If that sensor fails and no longer sends this information, then there’s no way for your Audi to know how hot or cold the coolant is.

This can cause the “Coolant Temperature too high” fault message.

Audi coolant temp sensors are known to fail prematurely and by far the most common cause for this fault.

Fortunately, this is an easy fix, all you need to do is replace the coolant temperature sensor which is usually found behind the coolant pipe on most Audis.

2. Bad Thermostat

The Thermostat is responsible for the opening and closing of the coolant valve inside your Audi. The thermostat regulates how much coolant can flow through the system by regulating its temperature.

If you have a bad thermostat, then it will either allow too much or too little coolant to flow through the system.

This could cause your Audi coolant to overheat if there is not enough coolant in the system, or underheat if too much coolant flows through it.

This is the second most common cause from my experience.

Other signs of a bad thermostat include:

  1. Extremely High Coolant Temperature Readings
  2. Coolant leaks below your Audi
  3. High Engine Temperature
  4. Unusual sounds from the engine

If the cause is a bad thermostat, then you will have to replace it. This is a relatively inexpensive process, but it will cost you about $50-$100 depending on where you buy your parts.

Labor will cost more because of the amount of work required to replace a thermostat on an Audi.

3. Failing Water Pump

After the coolant temp sensor and the bad thermostat, the third most common cause of a high coolant temperature reading is a failing water pump.

A water pump is a critical part of your Audi’s cooling system because it is responsible for circulating the coolant through the engine and back to the radiator.

It is possible that your water pump might be leaking or failing, which would cause your car’s temperature gauge to climb and display “coolant temperature too high”.

If you suspect this is the case, then it’s best to have a professional diagnose the issue so that they can replace the pump if needed.

You can either take your car to the nearest Audi dealership or you can find a mechanic near you that specializes in German vehicles.

If your Audi is still under warranty, then it’s best to take it to the dealership so that they can diagnose and fix the problem for free.

How to Reset the Coolant Temp too high message on an Audi

After you replaced the faulty component, you can reset the fault message by disconnecting the negative terminal of the battery and reconnecting it, or using an OBD2 Scanner to clear fault codes.

Once you’ve reset your Audi, it’s time to test-drive it and see if everything is working as expected.

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