Is Thermostat Necessary in a Car? (3 Potential Consequences!)

I don’t usually like bringing in personal experiences in posts, because I like keeping every article crisp, clear, and to the point.

But I hope you will forgive me for sharing and getting a little personal in this article for the simple reason that the context screams for it.

So, my first job was as Deputy Manager in a leading automobile firm that creates trucks.

Now, the reason I took that job is because I am fascinated by machines.

It’s so amazing how bits and pieces of metal can come together to create a mechanism that can run fast and carry heavy loads.

In my experience of working in the company, I learned how everything came together on the assembly line to build a full-fledged machine we call trucks.

And additionally, I also learned how to diagnose vehicle issues. It is here where I learned about the different sensors that are in place in different areas of the vehicle including thermostats which are more in line with what we are discussing today.

This isn’t the first I am discussing thermostats on this blog, but I am discussing thermostats in an operational capacity for the first time.

I will list my previous articles below.

So, is a thermostat really necessary in a car?

The absence of a thermostat will not result in the failure of the engine but with time the lack of a good quality thermostat will cause the engine efficiency and fuel economy to get reduced.

Now, I know this is a technical question and will require us to go a little more in-depth to understand the topic fully.

But I think I should give you a framework and will hopefully spark a thirst to know more about the topic.

Before we begin here are a few more articles that I think will complement this article on the purpose of a thermostat in a car.

Function of Thermostat in a Car

Now I know many of you already know the function of a thermostat in a car.

That’s perfect but for the sake of keeping the right flow for the article and to address potential beginners to the subject let me quickly tell you the function of a thermostat.

You see in simple terms; a thermostat is nothing but a switch that regulates the flow of coolant in the engine channels.

But you see when it comes to a complicated system like an engine every mechanism and sub mechanism is important.

The cooling system is one such important subsystem of an automobile unit.

Broadly, the cooling system in an automobile has three main functions.

  • To remove excess heat away from the engine.
  • To keep the operating temperature at a value wherein the engine performs most efficiently.
  • And lastly, to bring the engine to the optimum working temperature as quickly as possible for obvious reasons.

So, where and how does the thermostat come into the picture?

You see thermostat is kind of like a switch that aids the cooling mechanism to maintain the optimum operating temperature at which the engine performs best in terms of its efficiency.

What happens is, when you start the car and the engine is cold (as in when you start the engine in the morning) the thermostat prevents the coolant from reaching the radiator.

Because of the barrier, the coolant keeps circulating in the engine channels with help of the pump to enable the engine to reach the optimum temperature.

In other words, the coolant is enabling the engine to reach its optimum temperature fast.

It’s obvious now that in the absence of a thermostat or if it fails, the engine temperature won’t be able to reach its optimum operating temperature quickly.

So, a thermostat is like a valve that opens and closes as a function of temperature to maintain the optimum temperature.

I found this video that I think explains how the thermostat functions perfectly.

I hope you now understand the function of a thermostat in making the engine work optimally.

Effects of Running a Car without Thermostat

Now the big question that stands is what exactly happens if you drive a car without a thermostat.

Can you even run your car without a thermostat?

As I said, yes, it’s entirely possible to run your car without a thermostat, but you basically have no gate to control the temperature of the engine at optimal value.

This will ultimately result in the reduction of your engine’s efficiency and fuel economy.

So, the real question mutates into whether you want your car to perform at its best?

If the answer is yes, then continue driving the car but have getting the faulty thermostat replaced at the top of your priority list.

Now I know these are technical terms and I need to put some more light into the matter so that what I am saying is clear to someone who isn’t as technically aligned.

So, in much simpler terms what is it that you will experience in the absence of a thermostat eventually, if not immediately.

  • First off, the absence of a thermostat will result in improper heat exchange between the coolant and the engine.

This is because the coolant will not stay in the radiator to get cool enough and it will not stay in the engine channels to get hot enough, essentially rendering the exchange incomplete.

This will result in the overheating of the engine.

  • Secondly, if you continue to drive a car without the thermostat the engine will remain at a temperature around 50° (as opposed to the optimal temperature which is 80°C to 95°C).

Running the vehicle at this temperature will result in trapping of humidity, which condenses and blends with oil resulting in slush.

This slush more often than not will block lubrication and this will invariably cause in the wearing out of the entire system.

Therefore, the absence of a good quality thermostat will hamper vehicle performance.

  • And thirdly, a bad thermostat or absence of it can cause the Engine Control Unit (ECU) to function improperly.

You see an engine is a complicated mechanism with a number of moving parts all connected with each other.

Different parameters like temperature, pressure, etc. initiate different actions to make the engine function optimally.

The ECU assesses real-time readings from different places like the combustion chamber, intake, exhaust, catalytic converters, etc., and controls different aspects of engine operation.

In the absence of the thermostat, the car may burn more fuel as ECU will assess that the engine is still in its cool state and will initiate different actions to bring it to its optimal temperature when it should not.

ECU controls parameters like fuel/air mixture, timing, shift point, etc. with the help of different sensors running at a specified temperature.

With the thermostat gone, these temperature demands aren’t met forcing the ECU to balance the parameters on a cold engine all the time thereby reducing the car’s fuel economy.

When to Replace Thermostat in a Car?

So, now I think you can see how important it is to have a good quality thermostat in your car.

Yes, in the immediate sense a faulty thermostat wouldn’t stop you from driving the car but in the long term, it will impact the engine and thus vehicle performance in multiple ways.

So, how can one know it is time to replace the thermostat or at least check on it. What are some visible signs that you may need to replace the thermostat in your car?

  • The first and most obvious indicator is the ‘Check Engine‘ light on your dashboard.

If it is lit up, it implies something isn’t right with your engine. A car mechanic will have to run a diagnostic check to see what’s wrong.

But a malfunctioning thermostat will for sure enable the light to turn on.

  • Secondly, if you find that your car engine is overheating that again can be a direct indicator that your thermostat isn’t functioning properly.

The other extreme of this is equally true as well and indicates a faulty thermostat.

  • If your engine is running cold and you observe that your car seems to run out of fuel relatively quickly as compared to what you are used to, it would be a sensible decision to have the thermostat checked.

Now you don’t have to wait for something to go wrong with your car to check for a faulty thermostat.

You see most automobile experts agree, owing to the very design a thermostat can last for as long as 10 years.

But again, that is a very optimistic number.

In real life, there are so many other factors involved like weather, the way the car is driven, and faults with other engine parts that ultimately dictate how well or for how long the thermostat will work.

Unfortunately, there are so many people who tend to ignore a malfunctioning thermostat.

The simple reason is that they don’t see an immediate problem as the car is functioning normally in their perception.

What you need to remember is in a complex system like a car, every little problem tends to compound and eventually get bigger.

Therefore, I always urge people to have a simple diagnostic check every once in a while, from an experienced mechanic.

And the problem is in fact with a damaged thermostat, for the reasons listed above, you need to get it replaced immediately.

Car Thermostat FAQs

I hope I was able to put forth some real comprehensive insights for you when it comes to the question is thermostat necessary in a car.

Now I perceived the potential demand for clarity behind the question and arranged the article so as to address it properly.

That being said, let me quickly address a few more questions that I know spring about when you enquire about thermostats.

Can you run a car without a thermostat in summer?

During summer the engine will take a shorter time to heat up yes when compared to winter but again, in the absence of thermostat you won’t have the inherent control to keep the temperature of the engine at its optimal working temperature which will eventually lead to engine overheating and wear.

The core point to understand here is that the thermostat is like a gate or a valve that ensures that the coolant aids to keep the engine at its optimal temperature.

Now from using logic you may conclude because there is heat in the environment the engine will supposedly reach the optimal temperature easily. Which may happen but that leaves so much to uncontrollable factors.

And even if the engine reaches its optimal operating value, you have no control over keeping it there. Add the fact that the coolant will still pass-through way too quickly through the engine channels keeping the engine block prone to overheating.

So, it doesn’t matter what the environmental conditions are like it is still advisable to have a functioning thermostat in place.

Is thermostat needed in tropical countries?

Once again without a thermostat, your car will still run albeit with reduced engine efficiency and fuel economy. But in order for your engine to perform with good consistency and efficiency, you will have to have a functioning thermostat in place. Absence of which will render the control of the coolant loop non-functional.

What happens if you take the thermostat out of your car?

When you take the thermostat out you are basically taking away the control of the coolant loop which will cause engine efficiency and fuel economy to get reduced. Keep in mind the car will still function but will be susceptible to engine overheating, engine wear, and the development of engine hampering slush.

Now, if the question is posed because you have in some way diagnosed that your car is housing a faulty thermostat and it needs to be replaced, then for the time being you can drive the car without it.

But of course, for the numerous reasons that I have given in the entirety of this post on thermostats and their operation, getting your thermostat replaced must be your top priority.

I hope you found this article on is thermostat necessary in cars helpful and was able to provide you with the necessary clarity you expected from it.

See, I know this has been a little technical topic but let me tell you I have worked extra hard to make the article such that it appeals to people who probably aren’t that technically oriented.

But I think I have ventured around the technicality such that even people who have had hands-on on automobiles will find the information up to their expectations.

That being said, I am not perfect and there may be certain things that I might have missed or failed to address.

If you find anything or need anything addressed or a question in the context of thermostats, do let me know in the comments below.

Take care of yourselves and I will see you in the next one!


Electronics Engineer | Former Deputy Manager | Self-Taught Digital Marketer.Owner & Admin Of A Network Of Blogs and Global E-Commerce Stores

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