As temperatures rise and fall outside, it’s crucial that your vehicle’s internal engine temperature remains regulated — and that’s where the thermostat comes in. This small but important component works to control your engine’s temperature by opening and closing as needed. But what happens when it stops working properly? Can you still drive your car with a broken thermostat? We’ll explore this topic in detail so you can stay informed and be prepared.

1. Understanding the Role of the Thermostat in Your Car’s Cooling System

The thermostat is an essential component of your car’s cooling system. Its primary function is to regulate the flow of engine coolant through the system to ensure that your engine doesn’t overheat. In simple terms, the thermostat works by sensing the temperature of the coolant and then opening or closing the valve that controls the flow of coolant to the radiator accordingly.

How Does the Thermostat Work?

The thermostat is basically a temperature-sensitive valve. When the engine is cold, the thermostat is closed, restricting the flow of coolant to the radiator. This creates a closed system that allows the engine to heat up quickly and operate at its optimal temperature. Once the engine reaches its operating temperature, the thermostat opens, allowing the coolant to flow through the radiator, where it’s cooled by the air flowing over the radiator fins.

Why Is the Thermostat So Important?

A malfunctioning thermostat can cause a variety of problems in your car’s cooling system. If the thermostat fails in the open position, the coolant will constantly flow through the radiator, regardless of the engine temperature. This means that the engine may never reach its optimal operating temperature, resulting in poor fuel economy, reduced performance, and increased emissions.

On the other hand, if the thermostat fails in the closed position, the coolant won’t be able to flow to the radiator to cool down, causing the engine to overheat. Overheating can cause serious damage to your engine, resulting in expensive repairs and even engine failure.

In summary, the thermostat plays a crucial role in regulating the temperature of your car’s engine. If it’s broken or malfunctioning, it can cause serious problems and put your engine at risk. That’s why it’s crucial to ensure that your thermostat is in good working condition and to have it repaired or replaced promptly if any issues arise.

2. Signs of a Broken Thermostat and How to Detect Them

It’s important to know the signs of a broken thermostat in order to prevent further damage to your car’s engine. Some common signs of a faulty thermostat include:

  • Overheating: If your car’s engine is overheating or the temperature gauge on your dashboard is reading abnormally high, it could be a sign of a broken thermostat.
  • Cold air from heater: If your car’s heater is blowing cold air even when the engine is warmed up, it may indicate a bad thermostat.
  • Engine not reaching operating temperature: If your engine is taking longer than usual to warm up or isn’t reaching its normal operating temperature, it could be a sign of a faulty thermostat.
  • Erratic temperature gauge: If your car’s temperature gauge is moving up and down quickly or is stuck on one temperature reading, it could be because of a broken thermostat.

To confirm that your thermostat is the problem, you can perform a simple test. First, let your car warm up to normal operating temperature, then turn on your heater. If the air blowing out isn’t hot, it’s likely that your thermostat is stuck open or closed. Additionally, you can check your radiator for leaks or rust buildup to ensure that it’s not contributing to your car’s cooling issues.

If you’re experiencing any of these signs of a faulty thermostat, it’s critical to address the issue as soon as possible. Ignoring a broken or malfunctioning thermostat can cause severe engine damage or even engine failure, which can be costly to repair. In the next section, we’ll discuss the potential risks of driving with a faulty thermostat and the steps to take if you suspect that your thermostat is broken.

3. Potential Risks of Driving with a Faulty Thermostat

Driving your car with a broken thermostat can lead to several potential risks. It’s important to understand that the thermostat plays a crucial role in your car’s cooling system. If it’s not working correctly, it could cause overheating and affect other parts of your car’s engine. Here are some of the :

1. Overheating: A broken thermostat can cause your engine to overheat, which can lead to engine failure. Overheating can also cause your car’s coolant to boil, which can damage other parts of your engine and lead to further problems.

2. Reduced Fuel Efficiency: If your engine is constantly overheating due to a faulty thermostat, it can lead to reduced fuel efficiency. This is because your engine is working harder than it should be, causing it to use more fuel to keep the car running.

3. Increased Emissions: Driving with a faulty thermostat can also lead to an increase in emissions. If your engine is running too hot, it can cause incomplete combustion, which can release more pollutants into the air.

If you’re experiencing any of the symptoms of a broken thermostat or suspect that your thermostat is not working correctly, it’s essential to take immediate action. Ignoring the issue can lead to more significant problems down the line, including engine failure and costly repairs.

4. Steps to Take if You Think Your Thermostat Is Broken

If you suspect that your car’s thermostat is broken or malfunctioning, there are a few steps you can take to address the issue before it becomes a bigger problem. Here’s what you need to do:

Step 1: Check Your Temperature Gauge

The first thing you should do is monitor your car’s temperature gauge. If the gauge shows that the engine is running hotter than usual, it could be a sign that your thermostat is not regulating the engine’s temperature properly. Additionally, if you notice that your car’s heater is not producing hot air, this can also indicate a problem with the thermostat.

Step 2: Inspect the Thermostat

The next step is to physically inspect the thermostat. Check for signs of damage, such as cracks or leaks, that may be causing it to malfunction. If you’re comfortable performing DIY repairs, you may be able to replace the thermostat on your own. However, keep in mind that working on your car’s cooling system can be dangerous, so if you’re not confident in your abilities, it’s best to seek professional help.

Step 3: Have Your Car Inspected by a Professional Mechanic

If you’re still experiencing issues with your car’s cooling system, it’s best to take your vehicle to a professional mechanic. They can perform a thorough inspection to determine the root cause of the problem and recommend the most effective repair solution. Additionally, regular maintenance checks can help prevent potential issues with your car’s thermostat and cooling system.

By taking these steps, you can avoid potential hazards associated with a broken thermostat while ensuring that your car’s cooling system remains in good working condition. Remember, while it may be tempting to ignore minor issues, they can often snowball into bigger problems if left unaddressed.

5. Benefits of Timely Thermostat Repair and Maintenance

Regular maintenance and prompt repair of your car’s thermostat provide numerous benefits. Here are some reasons why you shouldn’t ignore the issue:

1. Improved Engine Performance

When your car’s thermostat is functioning correctly, it regulates the engine’s temperature and ensures that it stays within optimal limits. However, if it’s broken, your engine may overheat or run too cold. This can lead to poor performance, reduced fuel efficiency, and increased wear and tear on your engine. Therefore, timely thermostat repair and maintenance help keep your engine running smoothly, and prevent damage to vital engine components.

2. Better Fuel Economy

A faulty thermostat affects your car’s fuel economy negatively. Since your engine isn’t getting the right temperature regulation, it works harder and consumes more fuel than it should, even when you’re driving short distances. Moreover, an overheated engine can cause increased exhaust emissions, which exacerbate the environmental impact of your car. Repairing or replacing your thermostat can help you save money on fuel expenses in the long run and reduce your carbon footprint.

3. Longer Engine Lifespan

Your car engine is a complex machine that requires proper maintenance to extend its lifespan. A broken thermostat can cause rapid engine wear and tear, leading to more expensive repairs or even a complete engine failure. If you neglect your thermostat issue for a long time, it could lead to costly damage to your engine’s parts, such as the head gasket or cylinder head. A timely repair or replacement can prevent this issue and prolong your engine’s life.

In summary, ignoring your car’s thermostat issue can have several consequences, including poor engine performance, low fuel efficiency, and engine damage. Fortunately, you can avoid these issues by getting your car serviced by a professional or repairing it yourself if you have the necessary skills and tools. Keep in mind that timely maintenance and repair can save you a lot of money, in the long run, so don’t hesitate to take action when you suspect a thermostat problem.

6. Can I Temporarily Drive My Car with a Broken Thermostat?

If you have a broken thermostat in your car, it may tempt you to still drive it. However, this decision can have consequences and end up making the situation worse.

The short answer is: No, you should not drive your car with a broken thermostat.

When the thermostat fails, the engine won’t cool down properly, allowing it to overheat. An overheated engine can cause irreversible damage, leaving you stranded on the road or with an expensive repair bill.

What are the Risks of Driving with a Faulty Thermostat?

Continuing to drive with a broken thermostat can cause damage to the engine, leading to costly repairs. The most common risks of driving with a broken thermostat include:

  • The engine overheating and the possibility of a blown head gasket
  • Damaging the radiator or water pump due to the increased pressure
  • Reduced fuel economy due to poor combustion caused by an overheated engine

The radiator might blow up, or the car’s engine might seize up, making it impossible to start the car. Even if you experience none of these issues, the ongoing damage will lead to costly repairs in the future.

It is essential to avoid driving with a broken thermostat and seek repairs as soon as possible.

7. Professional vs DIY Thermostat Replacement: What’s the Best Option for You?

When it comes to replacing a broken thermostat, you have two options: hiring a professional mechanic or doing it yourself. Both options have their advantages and disadvantages, and the best choice for you will depend on your budget, skill level, and willingness to learn.

Professional Thermostat Replacement

If you’re not comfortable working on your car or don’t have the necessary tools and knowledge, hiring a professional mechanic is probably the best option. They have the expertise to diagnose the problem, replace the faulty part, and ensure that the cooling system is working correctly.

However, professional thermostat replacement can be costly, and you may need to pay for additional labor and parts. Plus, you’ll need to factor in the time it takes to schedule an appointment and drop off your car at the repair shop.

DIY Thermostat Replacement

If you have some mechanical aptitude and want to save money, replacing the thermostat yourself is a viable option. You can purchase a replacement thermostat online or at a local auto parts store and follow the manufacturer’s instructions for installation.

However, it’s essential to note that DIY thermostat replacement can be challenging, especially if you haven’t worked on your car before. You run the risk of damaging other components or installing the thermostat incorrectly, which can lead to more significant problems down the line.


In summary, whether you choose professional or DIY thermostat replacement, the most important thing is to take action as soon as you suspect that your thermostat is broken. Delaying repairs can cause extensive damage to your car’s cooling system, resulting in costly repairs and even engine failure. So, weigh your options carefully, and choose the method that works best for you and your car.

People Also Ask

What happens if I continue to drive with a broken thermostat?

If you continue to drive with a broken thermostat, your car’s engine will overheat, causing serious damage in the long run. Moreover, you’ll experience reduced fuel efficiency, decreased performance, and increased emissions.

Is it safe to drive a car without a thermostat?

No, it is not safe to drive your car without a thermostat. Although your car will still run, your engine will operate at a high temperature, which can cause severe damage and even result in engine failure.

Can I replace the thermostat myself?

Although replacing a car’s thermostat is not a complex task, it is better left to a professional mechanic to perform. An experienced technician can diagnose and repair any underlying issues that might cause your car’s thermostat failure.

How much does it cost to replace a car’s thermostat?

The cost of replacing a car’s thermostat varies depending on the make and model of your car. A new thermostat typically ranges from $27 to $200, while the labor cost may range from $50 to $150.

How do I know if my car’s thermostat is malfunctioning?

The most common symptoms of a malfunctioning thermostat include an overheated engine, low coolant level, poor fuel efficiency, and a heater that doesn’t work. If you notice any of these symptoms, you should take your car to a mechanic right away before more significant problems occur.


In conclusion, it’s not safe to drive your car if the thermostat is broken. Over time, it can cause severe engine damage and decrease your car’s performance. It’s best to have it checked and repaired by a professional mechanic to avoid any critical issues down the road.