Causes And Fixes For Fan Still Running When Car Is Off

Do you notice your fan still running when car is off?

It may be concerning for some people who just turned their car off, yet the fan simply would not stop. You probably have parked your vehicle, turned it off, but the fan continues to run. 

But the thing is that it is not at all a rare situation. In fact, it happens to many vehicles. However, this does not eliminate people’s concern about their vehicle. 

Today, we will discuss why exactly this happens and whether you should be worried or not. Let’s jump right into it.

fan still running when car is off

Fan Still Running When Car Is Off

First of all, keep in mind that your fan may continue to run even after a few minutes of turning your car off. This is not at all an error. What this means is that your engine is still being cooled by your fan. In fact, many automobile makes and models have this feature such as with the BMW, Toyota, and the Mercedes-Benz. The fan may run for about 3 to 5 minutes after turning the engine off.

When your engine is turned on, the coolant circulates and gets into your radiator. Once shut off, this prevents the coolant from flowing. Now, this can be bad since heat gets trapped while delaying the cooling process for your engine. 

This is why when your fan continues to run for a few minutes, this minimizes the risk of overheating. It cools your engine, which helps to promote its lifespan.

So, a few minutes of running the fan should be fine. What’s bad, however, is if the fans do not seem to stop running. It may have been running for several hours even after turning the engine. The risk is that your battery may drain completely, which is a problem.

Keep in mind that there are many factors that impact the performance of your fans. So, you need to look into the potential cause of the issue to provide the right solution.

1. Low coolant level

If your fan continues to run for a prolonged period even after turning the engine off, you may have a low coolant level. Your water pump tends to leak, and when this happens, the coolant level becomes low. Therefore, your fan keeps on running even after a few minutes. So, it is best to check the coolant level to address this issue.

2. Temperature sensor problem

Your vehicle has temperature sensors that help in controlling heat in your engine. It is located near your engine thermostat. It also measures the coolant release and the thermostat temperature. Thus, the system receives the temperature and sends it to the computer.

Afterwards, your computer utilizes this operating temperature data, which then results in modifying or operating your engine. So, the right temperature needs to be achieved to keep this system working properly. 

However, if the fans are not stopping even after several hours that you have turned the car off, it means the temperature sensor has a problem. So, it is good to inspect your temperature sensors’ operational status to determine what could be wrong with them.

3. Radiator issue

When there is damage to your radiator, this can also cause your fans to still run even if the car is off. For example, there may be cracks to the radiator hoses or the radiator itself. Additionally, there may be problems with your lower and upper radiator hoses such as wear and tear.

Over time, the hose and radiator pipe tend to deteriorate. As a result, the fans may not shut off even after turning the engine off. This is why the only thing left to do is to replace worn-out parts. By doing so, you can prevent further issues to the fan while improving its performance and lifespan.

4. Fan relay faults

Another thing to check if you have a fan still running when car is off is your fan relay. This is another component that impacts this problem, as it controls the electrical supply of your fan. The fans tend to malfunction when the relay component is broken. For example, the relay is rendered useless once it is stuck. 

So, if there is a need to repair or replace the fan relay, you may need to do so. Otherwise, this issue with the fan may persist and only get worse.

5. Defective ECU or PCM

Your vehicle has an ECU or a PCM that serves as its “brain” or center of control. So, if these parts are faulty, this can lead to fan issues. For example, the ECU or the PCM may fail to compute and recognize the data provided by the temperature sensor. Hence, the fans do not stop running.

6. Electrical wire concerns

Now, this is not a very common cause of fan issues – yet it can happen at times. There may be a poor connection to the electrical wiring, which is why you have fan malfunction issues. Depending on the issue, you may need to simply reconnect the wires or perhaps even replace them completely.

Read More: Will A Bad Fan Clutch Cause Ac Problems? Signs And Effects Of Bad Fan Clutch

Final Word

A fan still running when car is off is normal when it is only up to 5 minutes. This helps to cool your engine to prevent overheating. But if it runs for a longer period, then you will need to check possible causes of this problem.

Additionally, a broken fan may have to be replaced. It can cost about $300 to as much as $400, although it depends on the model and make of your vehicle and how serious the problem is. But overall, we do not recommend driving your car when the fan is damaged. This can lead to overheating of the engine, which can cause significant problems and safety issues. 

Therefore, be sure to have this issue with the fan resolved by a professional. By doing so, you can prevent further damage from happening while ensuring your peace of mind as you drive your car.

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