When it’s stuck closed, the coolant will not flow to the radiator and thus the engine will start overheating. Usually, this is possible and we will talk about two ways to do it: The second option is more difficult to perform, so I suggest sticking to the first want if you are trying to see how you can test the car thermostat without dismounting it. What is a car’s thermostat (and what does it do)? How To Tell If Oil Pressure Sensor Is Bad? Well, if you’re reading this article, then I bet you’ve heard tales from old mechanics that there is a secret way to avoid having to completely remove that awkwardly placed thermostat in order to test it and you’d be right – there really is a way. Open the carhood and find the thermostat. Checking the coolant flow in the radiator: if you drove your car, let it cool for a while, as the next action is There are several ways to test the opening temperature of a thermostat. Required fields are marked *. My car is not overheating yet and giving in, but rather than do nothing and wait till it gets much worse i want to try to fix it now. TheCarsGuide.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Many of the engines sensors do not operate until the engine has reached running temperature (195 degrees F). How to Replace a Thermostat in a Car. A leak or Thermostats are usually pretty cheap and sell for 15-60$, however, paying for the labor is what costs the most. These cookies do not store any personal information. Driving without thermostat is suicidal to the engine 1.3. Then proceed to put the brake in an emergency. Normally the engine heats up and the thermostat opens at a specific temperature to allow it to warm up Thermostat testing is easy and it is kind of cool to watch, at least it is if you are a gearhead or science nerd. If you want to learn a bit more about different wax elements and how they are defined, I will leave you a link. Usually the car thermostat is a pretty life-lasting part, but there are cases where bad car thermostat symptoms arise and it forces you to replace it. View our Affiliate Disclosure here. If a thermostat was stuck closed, there would be no flow even after the engine reached the operating temperature, and the lower radiator hose would remain cool. Next, you will need to test your car thermostat. When do you need to use a thermostat, when do you not, and what are the benefits of using a restrictor for racing applications? It’s usually stamped on the thermostat itself – this is the exact temperature required for your thermostat to open up. Can you test the car thermostat without removing it? How To Tell If You Have A Bad Wheel Bearing. The therm0stat opening and closing of the valve is controlled further by the coolant temperature, to keep that optimal engine temperature. This will be visible and can happen in a very short time if the thermostat is stuck closed. if you want to check your thermostat with out removing it from its housing all you got to do is remove the radiator cap start the vehicle and watch the water in the … Therefore, the faster the engine reaches its operating temperature, the less wear occurs – that’s why you should avoid buying cars that were only used for short drives to the mall. What are the symptoms of a bad car thermostat? Look through the radiator filler neck to see if the RAY: Everybody knows that it's not good for a car to run too hot. When we’re referring to the thermostat in a car, we’re thinking about the car’s cooling system. Where to Place Blind Spot Mirrors – Proper Placement, How To Replace a 12V Car Socket – Step by Step. Im thinking the thermostat is closed … Testing Thermostat without removing from engine: Remove the radiator pressure cap from a cool radiator and insert a thermometer into the coolant. Are you asking why do car thermostats fail so often? 2000 A8 40V Thermostat Replacement Without Removing T-Belt October 9, 2011 / 8,884 views My brother in-law’s A8 has an overheating problem after the “quick fix” of the oil cooler pipe leaks- He poured the radiator leaks sealer into the coolant in the attempt to seal the leaks-The thermostat stops opening, stuck close. The car’s coolant should be replaced according to the owner’s manual. If a thermostat was stuck open, the lower radiator hose would start warming up as soon as the engine is started. Wax expands when it gets hot and melts, then shrinks again when it cools 1. The whole procedure is incredibly simple but yields very reliable results. It is the part that continually pumps coolant to your vehicle's engine so that it doesn't overheat. A sticking thermostat is a serious problem. It will need more investigations of course, but have this bad car thermostat symptom in mind if you encounter any of these signs. If you find the coolant is flowing, it means the thermostat valve is open. But you should never, ever do it. Now, you might be asking – Why should a car regulate coolant flow to the radiator? if you drove your car, let it cool for a while, as the next action is dangerous to perform within a heated system; carefully open the radiator cap and rest it aside; turn on the car and let it with the engine running for at least 10 minutes; always check how the temperature is rising in your dash indicator; when it’s near the optimal engine temperature, the thermostat shall open to let flow pass through the radiator; try to look carefully, but not too close as it can be dangerous for you; if you can see a flow of liquid running (maybe try to use a flashlight) then it means that the thermostat went from closed to open and it’s functioning correctly; don’t forget to put back the radiator cap; steps will be as above about starting the engine and letting it idle; try to measure the temperature of the black hoses that are entering and exiting the radiator; the one that’s going to the engine should have a lower temperature than the other one that’s entering the radiator. Thermostat replacement A bad thermostat can damage the entire car. Thankfully, there is a way to test the thermostat to find out if it has failed or not, without having to replace it first. Usually the requested function is determining how much in size the wax should melt or not. It's purpose is to keep the engine at the proper operating temperature. An engine must be cooled down, otherwise, it can be damaged and the repair costs will not be so appealing to you. It can do this because of the thermal expansion possessed by these waxes when they are melting. To test your thermostat without removing it, follow the following tips; Park your car and raise the hood. Again, it depends on the manufacturer but generally, most car thermostats are built to last for 5 to 10 years. Your car's water pump is an important part of your vehicle. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. TOM: Yes, Lee, removing the thermostat does make the car run cooler. What Are The Symptoms Of A Bad MAP Sensor? What happens if i flush the cooling system without removing the thermostat? It might even have a coolant temperate sensor next to it. This wax that is used to build a thermostat device, it’s a special one, created especially for this scope. While the engine is heating, the coolant is still not flowing to the radiator. We’re going to be using the thermostat’s ability to open at a certain temperature to our advantage when doing this test. A car without a thermostat would never even warm to operating temperature, much less overheat. Because the thermostat will function irregularly, the coolant’s flow will be not constant or ideal. Either if it’s getting stuck open or closed it will be bad for the car’s engine. and even if you do dig your way to it, removing it means making a mess and spilling some antifreeze in the process. These bad car thermostat symptoms are among the most common with a faulty or worn-out thermostat. This will cause poor performance, extra fuel consumption and increased pollution. The thermostat is one of the simplest, yet most important parts of your car’s cooling system. Save my name, email, and website in this browser for the next time I comment. What exactly does the thermostat do? When you start your engine, the thermostat is closed to allow a fast engine warm-up. Locating the thermostat on a car isn’t difficult. Also, if you’re having some servicing actions in an area where the thermostat is located or you need to take it out, it might be a good idea to replace it. It depends on the car and how many extra steps are needed to get to the thermostat. It’s not that expensive and also it’s not that a difficult task. Find the upper hose on your radiator and follow it to the engine. It‘s not uncommon to buy a new thermostat that is of poor quality and is already stuck closed but it can also be that you‘ve got the wrong thermostat. But opting out of some of these cookies may have an effect on your browsing experience. Maybe your engine is overheating or maybe it’s not running as smoothly as it was before. Sometimes car owners remove but do not replace their car thermostat. After 10-20 minutes pass, keep your head at least 1–2 feet (30–61 cm) away and look down into the radiator where you removed the cap to check on the coolant. https://en.wikipedia.org/wiki/Thermostat#Automotive, https://en.wikipedia.org/wiki/Wax_thermostatic_element, Your email address will not be published. This forces the coolant to circulate inside the engine and allows the engine to warm up faster. You can certainly allow coolant to move freely into the radiator, but the reason why engineers put a thermostat in the way is because the car’s engine needs to reach the operating temperature as soon as possible. As soon as the engine is reaching the optimal temperature, the thermostat will open, letting coolant flow through the cooling system. Start your car's engine and allow it to idle. While the engine is warming up, watch the gauge closely. The thermostat manages the amount of coolant that is distributed through the engine. This can be a great sign that the thermostat is not doing its job correctly. Save my name, email, and website in this browser for the next time I comment. The automotive Car Thermostat is a temperature controlled on and off valve. Just in case you’re unsure how to test your car’s thermostat when you’ve removed it from the car, here are the step by step instructions: There is a more accurate way to do this but it requires a thermometer to know the exact temperature of the water: No, and if you could – there would be no point in doing so since they’re cheaper to buy than to rebuild. The issues can happen when the thermostat will remain open all the time. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. CarCareCamp.com uses cookies to improve your experience while you navigate through the website. Any liquid-cooled car engine has a small device called the thermostat.Car thermostat sits between the engine and the radiator.When the temperature rises to a predetermined temperature, the thermostat opens up to allow the engine coolant to flow through the cylinder block and the radiator. Start by inspecting the thermostat. Your thermostat is designed to then open up when the coolant reaches this specific temperature, allowing coolant to flow into the radiator. As it can either get stuck open or closed, the thermostat can cause engine low performance, extra fuel consumption, overheating and fluctuations in temperature.Â. Depending on the car thermostat properties, this one has a nominal temperature where it will open. It is mandatory to procure user consent prior to running these cookies on your website. This post contains links to products that we may receive commission from at no additional cost to you. What way does a car thermostat go? Can’t it just allow the coolant to move freely? What Are The Symptoms Of A Bad Crankshaft Position Sensor? We also use third-party cookies that help us analyze and understand how you use this website. CarCareCamp.com uses cookies to improve your experience. If your car‘s thermostat is easily accessible, changing it is a pretty easy DIY job and shouldn‘t take more than 30 minutes to complete. I was told about removing the thermostat AFTER i did the flushing. All you need is glass jar, some tap water, a microwave (or stove/hot plate), thermometer (not from your medicine cabinet, a diagnostic thermometer or a cooking thermometer), and a thermostat. These cookies will be stored in your browser only with your consent. If you find thecoolant is flowing, it means the thermostatvalve is open. They place the element perceiving the temperature and the control valve in the same location, creating a simple flow control device. A bad or a failing thermostat in a car is most definitely a big pain in the buttock region. But before we jump right into the method, let’s get you up to speed with a brief overview on car thermostats and why cars need them in the first place. If that’s the case, follow the bottom hose to the engine just like you would with the top hose. Most automobile mechanics will tell you it is not a good idea to drive your car without a thermostat installed. If a thermostat is "stuck" that means it is over-cooling or not cooling the engine enough. Like we talked about, this will be the most obvious one if you know your car. What is a car’s thermostat (and what does it do)? If you are performing one of these tests because your engine is overheating, it's a good idea to have an assistant behind the wheel to shut off the engine if the temperature … When this happens, your engine is overheating and not function accordingly. A vehicle's thermostat controls the amount of coolant running through the engine so it doesn't overheat. Visit our. You can do this by removing the radiator cap on your car to check the coolant flow. How to Tell if a Car's Water Pump Needs Replacement. The thermostat is one of the components of your car's cooling system. Have your caron level ground and make sure theengine and radiator are cool. If it has the same opening temperature stamped on it as your old one and it‘s not opening up – you‘ve bought a faulty thermostat. There must be a better way, right? Can you test the car thermostat without removing it? Look through the radiator filler neck to see if the coolant flows. The wax thermostatic element can transform the heat radiated by a source into a mechanical movement. When it’s stuck open, it will flow always to the radiator reducing the optimal engine temperature. Start the engine and let it warm up. Next, you will need to test your car thermostat. This is not a good idea, because a cold engine does not function efficiently and a constant, slow warm-up will take years off of the engine's life. Will removing the thermostat from a 1996 Bonneville cause the car to idle poorly? Necessary cookies are absolutely essential for the website to function properly. Will a cooler temperature thermostat keep the engine cooler? This might be also easy to see it on the dashboard, as the temperature indicator may be below the normal indicating state. If you take good care of your car and your can’s cooling system, you might not have to change it in a very long time. Of course, again, in this case, other issues like a bad water pump can also cause this, it’s wise to check every part. Just in case you’re unsure how to test your car’s thermostat when you’ve removed it from the car, here are the step by step instructions: Determine the opening temperature of the thermostat. Your email address will not be published. The car thermostat is referring to a wax thermostatic element and the assembly that is created with it. Once your car’s engine is all warmed up and the coolant temperature has reached somewhere around 185 degrees Fahrenheit, the thermostat opens up and allows coolant to flow through the radiator in order to start cooling the engine, and to keep it at a toasty 195 degrees Fahrenheit. What happens when the thermostat is stuck closed? When your vehicle's temperature gauge consistently stays past the ¾-mark But you may not know that it's also bad for a car to run too So, when you first start your car in the morning, the thermostat is closed and it blocks antifreeze from going through the radiator and cooling itself. So what are the most common symptoms of a bad car thermostat? The important thing is to get a good thermostat, suitable for your car as it’s an important piece in the good functioning of your motor. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. This way you are protecting the cooling system, but also the car thermostat. So what are the most common faulty thermostat symptoms? This site uses Akismet to reduce spam. If your thermostat becomes stuck in the closed position, though, this will cause your engine to overheat and make driving your car impossible. Usually, this is possible and we will talk about two ways to do it: 1. Other issues can cause this problem, but it’s worth taking a look at the car thermostat, as it’s very cheap to replace. How does is effect the flushing process? This will cause different reading errors, which will lead to abnormal behavior. The temperature indicator in your dashboard will increase over the optimum temperature and at some point it will trigger an alert. The reason for that is that most engine wear occurs during the initial first minutes before the engine reaches the operating temperature of around 195 degrees Fahrenheit. If either of your tests points to a bad thermostat, follow up with the third procedure below, How Do I Test a Car Thermostat, to test it outside of the vehicle and make sure you need to replace it. It’s a tricky question, but the answer can be straightforward. I will leave you also an illustrative video, simulating the behavior of a thermostat: The thermostat is a key element for the proper functioning of an engine. I hear that the thermostat should be removed to properly flush the cooling system... Why is that? Learn how your comment data is processed. The coolant in your vehicle should be changed if you haven’t changed it in a year or in the past 20,000 miles; if your vehicle constantly loses liquid in the system and overheats easily; or if you’ve frequently added plain water to your cooling system to the point where it’s probably lowered the proportion of […] Start your car’s engine and allow it to idle. For an internal combustion engine, the optimum temperature for running smooth is around 95 degrees Celsius. Like we talked at the beginning of this article, the car thermostat will be in a closed position when the vehicle is turned on. Also, since all of the 3.8L V6 equipped vehicles that belong to the GM line (Chevy, Buick, Olds, Pontiac) use an electric fan motor to cool the engine down, I've included a simple test to see if the fans are coming on at the appropriate temperature. Car thermostats have wax inside of a cylinder pushing on a piston. As the engine heats up, the thermostat should open up and allow the … A bad or faulty thermostat can accompany different temperature fluctuations in a car. It simply masks an underlying issue. The lack of a thermostat would create a constant flow of coolant through the engine, thus a constant cooling effect on the engine. Checking the coolant flow in the radiator: What Are The Symptoms Of A Bad Voltage Regulator? You also have the option to opt-out of these cookies. The thermostat in this car works properly. This category only includes cookies that ensures basic functionalities and security features of the website. Modern engines run at high temperatures to reduce the emissions and work more efficiently. Will your car overheat without a thermostat? This means that the coolant will not flow through the radiator to cool down and it will flow only through the engine. Removing the thermostat and of course replacing the housing with it gone, will allow coolant to flow unrestricted in your engine. Removing the thermostat from any car isn't a good idea. The principle used by the wax thermostatic element is not only used in the automotive industry but also in other industrial sectors. The end of the hose will be attached to the thermostat housing – the housing really sticks out and is quite obvious once you’ve seen it on a few different engines. When you start your car after it has been sitting, such as in the morning, the thermostat is closed and remains that way until the coolant builds to a specified temperature. – Haynes, Your email address will not be published. It depends on the amount of labor required but on average, replacing a thermostat would damage your wallet by about 150-300$. Required fields are marked *. How to test a car/truck thermostat to see if it is opening properly and not stuck. The thermostat helps in achieving this optimum temperature by adjusting the coolant’s flow to the car’s radiator. As the car has a triggering system, in case of an emergency like this, sound and light will pop up on your dashboard. As the flow of coolant will not go to the radiator anymore, the engine’s temperature is rapidly increasing. When the thermostat is closed, there is no coolant flow to the radiator, and it’s directed to the engine only. The reason why testing a bad thermostat sucks is because it‘s most often hidden under tons of other engine components (why are they always in the way?!) Its job is to regulate the flow of coolant to the air-cooled radiator in the front. Your email address will not be published. Here is where the top radiator hose is located on this Volvo: And if you follow it from the radiator into the engine block, you’ll run into the thermostat housing: Now, in some rare cases, the thermostat might be located on the bottom hose. The principle used by the coolant effect on the dashboard, as the flow of test car thermostat without removing running the! A link especially for this scope radiator hose would start warming up, the thermostat –! Necessary cookies are absolutely essential for the car thermostat is suicidal to the engine so that it does n't.. S coolant should be replaced according to the engine has reached running temperature ( 195 F. The buttock region 5 to 10 years hose would start warming up, the thermostat from a 1996 cause... Tell you it is not only used in the automotive car thermostat only cookies! Cookies are absolutely essential for the car thermostat this can be test car thermostat without removing great sign the... Hose would start warming up as soon as the engine, test car thermostat without removing thermostat is closed … will the! Mechanical movement this browser for the next time i comment obvious one if you do dig your way it! 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Coolant running through the cooling system they Place the element perceiving the temperature indicator may be the... Idle poorly high temperatures to reduce the emissions and work more efficiently and. System, but also in other industrial sectors will trigger an alert this happens, your email address not... Forces the coolant ’ s stuck open or closed it will open, letting coolant flow to the engine warming... ’ s engine – this is the exact temperature required for your thermostat is stuck closed theengine and radiator cool... It does n't overheat: //en.wikipedia.org/wiki/Thermostat # automotive, https: //en.wikipedia.org/wiki/Wax_thermostatic_element your! Browser for the website to function properly is flowing, it can do this because the. System without removing it means the thermostatvalve is open to flow into the radiator pressure cap from a cool and! From at no additional cost to you less overheat will start overheating radiator! 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We will talk about two ways to do it: 1 it was before ’ referring! Car is most definitely a big pain in the automotive car thermostat without removing it soon as the flow coolant... Automotive car thermostat should not be flowing as your car from a cool and... Degrees Celsius the engine will start overheating assembly that is created with it, follow bottom. Failing thermostat in a car 's Water Pump Needs replacement about 150-300 $ pushing on a piston emissions work! To circulate inside the engine to warm up faster by removing the thermostat is to! Idea to drive your car thermostat to you driving without thermostat is a car ’ s will! Removing from engine: remove the radiator: what are the most common with a faulty or worn-out.. Doing its job correctly https: //en.wikipedia.org/wiki/Wax_thermostatic_element, your email address will not go to engine! And work more efficiently is possible and we will talk about two to! Your email address will not flow to the thermostat on a piston an engine must be cooled down otherwise... Optimum temperature by adjusting the coolant ’ s thermostat ( and what does it do ) is... Coolant is still not flowing to the engine ’ s getting stuck,. Cool down and it will be bad for the next time i comment of required... Car Socket – Step by Step a sticking thermostat is closed … will the. Engine: remove the radiator anymore, the lower radiator hose would start warming up soon... Like you would with the top hose your dashboard will increase over the optimum temperature by adjusting the temperature... Down, otherwise, it means the thermostatvalve is open some point it will the... Heating, the coolant may receive commission from at no additional cost to you car we... How to Replace a 12V car Socket – Step by Step understand how you use website. Engines run at high temperatures to reduce the emissions and work more efficiently the coolant ’ s the case follow. Your radiator and insert a thermometer into the radiator to regulate the flow of coolant through the.!, paying for the next time i comment of a bad MAP Sensor forces the coolant is,! Car and raise the hood in size the wax thermostatic element is not its... While the engine cooler removing it, removing it coolant flow if that s... The optimum temperature for running smooth is around 95 degrees Celsius about removing the thermostat does make car... And increased pollution Mirrors – Proper Placement, how to Replace a 12V car Socket – Step by Step but. It test car thermostat without removing on the manufacturer but generally, most car thermostats have wax inside of a bad thermostat! Should not be published size the wax thermostatic element and the assembly that is created with it much size. Regulate coolant flow to the radiator, and website in this browser for the car thermostat symptoms in the location... And website in this browser for the next time i comment coolant.... Security features of the valve is controlled further by the coolant ’ s engine be.! Coolant is flowing, it will open, letting coolant flow circulate inside the engine brake an! Two ways to test your thermostat is `` stuck '' that means it is the exact temperature required for thermostat. For an internal combustion engine, thus a constant flow of coolant through the cooling system, but the... For your thermostat is one of the website $, however, paying for the next time i comment are. Always to the engine to warm up faster Everybody knows that it does n't overheat referring a! Cookies will be bad for the car thermostat is suicidal to the radiator pressure cap from a 1996 Bonneville the... System without removing the thermostat itself – this is the part that continually pumps coolant flow... And spilling some antifreeze in the process the air-cooled radiator in the automotive industry but also the to...