Thermostat Replacement Interval, Symptoms, Diagnosis, And Replacement!

Have your car started overheating lately and you are asking yourself more about the thermostat replacement interval? Well, if that is the case, then you are at the right place because, in this article, there will be quite a bit to cover on this topic.

• Cooling System
• Thermostat Function
• Thermostat Location
• Problems
• Stuck Closed
• Stuck Open
• Diagnosis
• Replacement Interval
• Replacement Process
• Conclusion
• FAQ

Performing thorough research when you come across a problem with your car is always a good idea. You just don’t want to end up paying thousands of dollars on greedy mechanics. Especially when the problem is something quite simple as a thermostat.

And even though this device is rather simple, when it goes down, things can escalate rather quickly. This is why it is often advisable that you check the coolant level, as well as the temperature gauge on your car all the time. We are going to explain why in a minute. But first, let’s discuss more about what we are going to cover in this article.

In this article, we are going to cover how the car cooling system works and the thermostat function in the car. Then we will cover the location and after that, we will discuss the thermostat problems. We will learn from what type of problems this component is troubled with and the right thermostat replacement interval. Also, how much money will cost to replace this thermostat?

How Car Cooling System Works – Thermostat Replacement Interval

Now before we dive into more complex topics like the thermostat replacement interval, let’s take a look at some basic topics and learn about the car cooling system. How this system works and what is its purpose for the automobile? Let’s explain.

Car cooling system, as its name implies, has the purpose to cool the engine down. Inside the engine, there is the combustion, and as you know flames are raging during the combustion process. So, if there isn’t something to cool off the engine, the engine will eventually overheat.

This is why you need a cooling system in your car. And not only that, but you also need the cooling system in top shape all the time. Remember that. Because one long ride with a bad thermostat and your engine could go to the junkyard.

Nevertheless, this cooling system consists of the thermostat, upper and lower radiator hoses, radiator, as well as a water pump.

This is simply a circulating system where coolant circulates in and out of the engine. The water pump is basically doing all the heavy lifting when it comes to cooling.

And not to forget the radiator through which the coolant goes in and the air basically cools off this fluid and then the coolant is brought back to the engine. But where the thermostat comes into play? Let’s elaborate more on that next before we learn about the thermostat replacement interval.

Car Thermostat Function

Now before we cover the thermostat replacement interval, let’s take a look at the thermostat function. Let’s understand what is the function of this component in your cooling system.

The thermostat in general is a switch. This switch activates based on the temperature of the coolant in your vehicle’s engine.

The thermostat has a sensing device inside and a spring that is activated based on the temperature inside of the engine.
When you do a cold start and the coolant is cold from sitting all night, the water pump will only circulate the coolant that is found inside the block. So, this means that the thermostat is closed.

But as the engine warms up, the coolant will warm up as well. So, in order for the engine to avoid overheating, the thermostat will open and will allow the hot coolant to be circulated inside of the engine in the radiator and then be brought back into the engine.

The thermostat is not an electronically activated device. This means that it is not connected to the computer and the computer does not know if the thermostat opens and closes well.

So, this is why this problem is rather difficult to solve, and sometimes it is useful for you to learn the thermostat replacement interval and replace this component in order to avoid some problems with it failing.

Car Thermostat Location – Thermostat Replacement Interval

We have covered the thermostat function, now let’s take a look at the thermostat location before we learn more about the thermostat replacement interval.

So, where the thermostat is located? The thermostat is usually placed under the thermostat housing. This housing is located usually where the upper or lower radiator hose is attached to the engine.

The mounting location really depends on the application and how the manufacturer designed the engine.

So, following the radiator hoses and where they are attached should be a good lead. The thermostat housing is basically a spherical component that is attached to the engine block. And underneath this component, the thermostat is mounted. But what is the thermostat replacement interval? More on that, we are going to cover more in a bit, after we discuss the car thermostat problems.

Car Thermostat Problems

Now let’s take a look at the thermostat problems before we discuss the thermostat replacement interval.

There could be two situations when the thermostat does not work. It could end up stuck closed or stuck open. Both of these situations produced different symptoms and problems. And in the following chapters, we are going to cover all of these problems in detail and see what you can expect when the thermostat fails.

Car Thermostat Stuck Closed

Now let’s first cover the problems when the thermostat is stuck in a closed position. So, what a closed position means?

Well, this is the situation when the thermostat is stuck closed and does not allow the coolant to circulate and exit from the engine block. This means that the water pump is only circulating the coolant inside of the engine block and the coolant is not cooled off properly. So, let’s cover these symptoms when you have a closed thermostat before we cover the thermostat replacement interval.

1. Overheating Engine

The first symptom of a thermostat stuck closed before we cover the thermostat replacement interval is the situation when you have an overheating engine.

When the coolant does not circulate outside of the engine, you will have problems with the temperature readings.

The temperature gauge will go in the red zone when this happens and the engine will tend to overheat. So, if you notice a warning about the coolant temperature from the computer, or possibly you notice the gauge in the red zone, it is important to stop quickly and make sure that you don’t drive the car because the more you drive, the worse the problems would be. This is why learning the thermostat replacement interval is so important. But more on that, we will cover more in a bit.

2. Loss Of Performance – Thermostat Replacement Interval

The second symptom closely associated with the problem of a stuck thermostat is the loss of performance. So, why is this the case?

Well, as you probably know, the engine needs to be at the proper working temperature in order to function well.

So, if the thermals inside of the block are not at the recommended specs, the engine will not be producing the amount of power that you need. In this case, you will have a poorly performing engine that will be slow to respond, and eventually, it will destroy itself from the inside. That’s why it is hugely important to learn the thermostat replacement interval and replace the thermostat on your car before it is too late.

3. Blown Head Gasket

The last symptom that is closely associated with the closed thermostat is the blown head gasket. So, why is this the case?

Well, the head gasket as you probably know is the component that sits between the engine head and the deck of the block.

So, when the engine overheats, the head starts to warp and the critical point is always the head gasket. Engine coolant will start to escape from the head gasket.

In these situations, good resurfacing of the engine head is needed to make it smooth, and also a new head gasket has to be installed. And this is quite expensive work, to be honest. This is why the thermostat replacement interval is needed in order for you to avoid situations like this.

Car Thermostat Stuck Open

The next situation that we are going to cover is the situation when you have a thermostat stuck in an open position. So, what does this mean?

Well, this means that you need to learn the thermostat replacement interval. The thermostat is stuck in an open position and allows coolant flow non-stop.

Immediately after you start the engine the coolant will start to move inside and outside of the engine. And this is also a situation that you want to avoid. Even though, this is a preferred way for the thermostat to fail because your engine will not overheat in this case. But it will cause some other symptoms that we are going to cover next.

1. Engine Failing To Reach Operating Temperature

Now let’s cover the first symptom that requires knowing the thermostat replacement interval. And this is the situation when the engine fails to reach the operating temperature. So, why is this the case?

Well, if the thermostat is non-stop open and cold coolant is pushed into the engine all the time, the engine will struggle to get to operating temperature.

When this happens, the engine will run very rich since the engine coolant temperature sensor will register a cold signal.

So, instead of the usual 2-3 minutes for the engine to reach operating temperature, there will be 15 to 20 minutes before it does so. And this is a big difference.

The engine will run really rich and you will basically struggle until it warms up. So, if the engine has trouble warming up properly, then this is a sign of a bad thermostat that needs replacement. But more on the thermostat replacement interval and the replacement, we are going to cover in a bit after we cover the last symptom.

2. Heater Does Not Work

The next symptom of an open thermostat that we are going to cover is the situation when you have a heater core that is not working or is slow when it comes to increasing the temperature inside of the cabin. So, why is this the case?

Well, this is the case because whenever you have a properly working thermostat, it is enough for you to drive a mile or two in order for the heater to start blowing hot air. But if the thermostat is open, you will not be able to heat up the cabin this quickly.

In these cases, it might take 10 minutes and then still, the heat will not be good enough because the coolant will not get up to proper working temperature. This is why it is important that you should look for the thermostat replacement interval and replace the component. But how you can diagnose this component? Let’s elaborate more on that next.

Car Thermostat Diagnosis

When it comes to the diagnosis of the thermostat, it is important to take into note the fact that this thermostat can be stuck in an open or closed position.

If the thermostat is truck closed, your temperature gauge will go into the red zone much sooner than previously. So, in other words, the engine will overheat quite often and you could blow a head gasket.

While on the other hand, when you have a thermostat that is stuck open, you will have a problem like a difficulty starting the engine, the car running rich all the time, increased fuel economy, the smell of gas, temperature gauge not being at the right operating temperature, and other minor symptoms.

Not to mention the check engine light and the code P0128 which indicates the coolant temperature below the recommended temperature level. And this is a clear indication that the thermostat is broken.

This is why whenever you have one of these symptoms, it is safe to assume that the thermostat is broken and you need to learn the thermostat replacement interval. But what is the right thermostat replacement interval? Let’s elaborate more on that next.

Thermostat Replacement Interval

We covered the thermostat symptoms and also how you can diagnose this component. So, what is the right time to replace this component, in other words, what is the right thermostat replacement interval?

The replacement interval of the thermostat is about 10 years. Even though sometimes these thermostats can last for the whole lifespan of the vehicle.

But from our experience, it is best to replace them when you are doing the water pump and timing belt or chain. Why so?

Well, since you are already there and flushed all the coolant, why not replace the thermostat? Thermostats are very cheap. So, you shouldn’t go cheap on these components because if you go for the very low-end parts, you will get a low-end lifespan and your engine will overheat at some point. This is why it is best to go for quality OEM parts when it comes to components like this.

Car Thermostat Replacement

When it comes to replacing the thermostat, we can say that this procedure is rather easy. You just need to locate the thermostat housing that is bolted on the front side of the engine in most cases.

Then, you need to remove the coolant hose and once you did that, you can remove the thermostat housing and remove the thermostat from its place. Install the new one and repeat the procedure.

Once the thermostat is replaced and everything connected, remove the cap from the coolant expansion tank and let the car run for a minute or so. This will clear the air and you will need to top off the coolant to make sure that the level is nice and even.

Conclusion To Thermostat Replacement Interval

In this article, we covered quite a lot when it comes to the car cooling system. First, we learned how the cooling system works and what is the function of the thermostat.

Then we learned more about the problems that are associated with the thermostat. As we noted, there are two situations. The first is when the thermostat is stuck closed and your car tends to overheat. Then we covered the second problem when the car thermostat is stuck open. And the second problem indicates that your car is having difficulties reaching operating temperature and also, in this case, the heater core will not function well.

Once we cleared the symptoms out of our way, we then moved on and learned about the thermostat replacement interval. And noted that this component is good for about 10 years or so. Sometimes even more.

Lastly, we focused on the replacement of the component. Replacing the thermostat is not something difficult. But it still requires clearing the system out of the air and also making sure that the new thermostat works well. Sometimes these components can come defective from the factory. This is why you shouldn’t trust it too much until you make sure that it opens and closes well as it should.

FAQ

What Are The Signs Of A Bad Thermostat?

Many signs can indicate a bad thermostat. When this component breaks it either ends up being open or closed. If the thermostat is open, you will have a lot of trouble reaching the normal operating temperature. Especially in cold weather, the engine will run poorly and could even stall. On the other hand, if the thermostat is closed, your car will tend to overheat. This will result in high temperature readings and a blown head gasket. So, it is smart to react whenever the temperatures reach high levels.

What Happens If I Don’t Replace My Thermostat?

This really depends on whether the thermostat is open or closed. If it’s open and water circulates all the time, the engine will find it difficult to reach operating temperature and will run pretty poorly. On the other hand, if the thermostat is closed, the engine will tend to overheat and it can fail the head gasket.

Do Thermostats Go Out Often In Cars?

Not quite, usually OEM thermostats last for more than 100,000 miles or 10 years. The best thing is to replace the thermostat on your car when you do the water pump service. This way, you will be sure that you will not face a thermostat failure in the near time.

When Should I Replace My Thermostat?

When you do the water pump service, it is a good idea to replace the thermostat as well. If not, you will have to replace the thermostat when it starts to fail and the car has problems with the operating temperatures.