If you are getting an “engine overheated idle engine” fault message on your GMC, Chevy, or Buick, then this article is for you.
After working on a handful of GM cars that have this fault message, I’ve figured out the most common causes for this issue.
In this article, I am going to go over the leading reasons why your GMC, Chevy, or Buick is showing an engine overheated idle engine message. Let’s get to it
What Does “Engine Overheated Idle Engine” Fault Message Mean?
In short, If you encounter the ” Engine Hot Idle Engine” message on your driver information center, it simply means that your engine has become too hot to operate as it should.
You must idle the car in order to cool the engine to avoid further damage. Once the engine returns to a safe operating temperature, you can try to drive.
This issue is a common problem that affects Chevy, GMC, and Buick vehicles and can be resolved with the appropriate steps.
Based on my experience as a mechanic I can say in most cases the engine is not damaged, but it is necessary to cool the engine before restarting.
What Causes the “Engine Overheated Idle Engine” Fault Message?
Now, that I have told you what the fault message is, let’s talk about why it appears.
Faulty Engine Coolant Temperature Sensor
The most common cause of this problem is an engine temperature sensor that has failed or is malfunctioning.
The Coolant sensor tells your vehicle’s computer (ECU) engine is, and if it is too hot or too cold.
The ECU will then adjust its output signals to maintain an ideal operating temperature.
When the sensor fails or malfunctions, the ECU cannot accurately determine whether the engine is too hot or too cold. As a result, The Engine control module may think the engine is overheating even if it is not.
This will cause the “engine overheating idle engine” message to appear on your vehicle’s instrument panel.
2. Bad Thermostat
The second most common cause of the “engine overheating idle engine” message is a bad thermostat.
The thermostat is a small valve that regulates coolant flow to your engine.
It allows coolant to enter the engine when it gets too hot and then closes off again when it returns to normal temperature range.
When this valve malfunctions or fails, it can cause the engine to run hotter than normal, which causes the message to appear on your vehicle’s instrument panel.
3. Low Coolant Level
Coolant is responsible for keeping your engine’s temperature at a safe level.
The coolant circulates through the radiator and engine block, where it absorbs heat from the combustion process.
As this happens, the coolant is cooled by a fan blowing air across its surface and then returned to the radiator through hoses to repeat this process again.
If the coolant level drops too low due to potential leaks or poor maintenance, the engine will overheat. When this happens, you’ll see the message on your dashboard.
4. Radiator Leak
The final common cause of the problem is a bad radiator due to leaks.
A radiator leak is one of the most common causes for a vehicle’s temperature gauge to rise.
The radiator cools your engine by circulating coolant through its tubes and fins, where it absorbs heat from the combustion process.
If there are any leaks in this system due to damage or wear, hot air will escape into the engine bay instead of being cooled and returned back into the cooling system.
This will cause your engine to overheat and cause the engine overheated idle engine fault message.
How Long Should You Idle the Engine after Seeing the Overheating Message
When it comes to the actual time it takes for the engine to cool down after overheating depends on several factors, such as the temperature outside and the condition of your cooling system.
However, on average it will take around 30-40 minutes for your engine to cool down after overheating.
If you’re parked in the shade and it’s a cool day outside, then it will be less than that.
If you’re parked in direct sunlight on a hot summer day, then it could take longer than 40 minutes to cool down.
How to Fix and Reset the Engine Overheated Idle Engine Warning
The first thing I recommend you start with is resetting your car by disconnecting the battery for about 5-10 minutes. Then, reconnect the battery and start your car up and see if the message goes away.
If it doesn’t, then you may have a problem with the temp sensor, fortunately, the sensor is about $15-20 and relatively easy to replace.
If replacing the coolant temperature sensor then this might be caused by a bad thermostat or radiator. I recommend taking the car to a Dealership/Independent mechanic to have them diagnose the problem.
Additional Sources
https://www.carrchevrolet.com/service/information/reasons-a-car-may-overheat-beaverton-or.htm
https://www.delphiautoparts.com/gbr/en/toolbox/what-temperature-sensor
https://www.jdpower.com/cars/shopping-guides/what-is-a-radiator-in-a-car