Do I need to Change My Car Thermostat?

car thermostatThere are a lot of routine maintenance items that need to be done on your car.  These include things to listen to, things to replace on a regular basis and things to check to make sure they aren’t wearing out.  We have a series of articles about the routine maintenance checks you should be doing on your vehicle every week, every month and every six months.  If you’re interested you can start by reading our first article about weekly routine maintenance.

When it comes to your car thermostat, it actually falls outside of the routine maintenance category.  The thermostat in your vehicle will most likely not wear out or become less effective over time due to normal driving.  Your thermostat is a pretty simple piece of equipment with a pretty simple job.  Your thermostat is a valve on your vehicle’s cooling system which regulates how much of the coolant gets recirculated straight back into the engine and how much gets sent out through your radiator to be cooled before it recirculates through your engine.  By modulating how much coolant gets sent through the radiator, the thermostat can keep the temperature of the coolant in your engine in a very specific range no matter how warm or cold it is outside.  This specific temperature range is the range your engine is designed to operate most efficiently in, getting the maximum power without overheating and damaging any parts.  This is usually about 1800F to 2000F.

A car thermostat opens and closes through the use of a bimetallic spring, a wax piston or other thermally controlled device.  In a bimetallic spring, there are two different types of metal bonded together.  These two types of metal expand at a different rate when they are heated, so as the engine coolant warms up the two metals expand, one to a different length than the other.  This causes the spring to straighten which pushes the valve open.  Similarly in a wax cylinder there is a wax that melts right around the temperature your engine should operate.  When the wax melts, it expands pushing on the cylinder which moves and opens the valve.

Both of these mechanisms are so simple that there is very little to break, change, or go wrong.  There are however some situations where you need to replace the thermostat in your vehicle.  If your car ever overheats, it could cause damage to your thermostat.  Every vehicle has a temperature gauge to help you make sure your vehicle’s engine is operating in the proper temperature range.  If the temperature gauge ever gets more than ¾ of the way up its range, or reaches the red line, you have probably done damage to your thermostat.  High temperatures can ruin the bonding on the bimetallic spring or change the properties of the wax cylinder so your thermostat won’t open at the specified temperature it is supposed to.

Car ThermostatIf either of these situations happen to your car it may be worth replacing your thermostat.  Replacing a car thermostat includes the draining and refilling of your vehicle’s cooling system so you may also consider performing a cooling system flush while you are replacing the thermostat.  Flushing the cooling system of your car can help remove the buildup and deposits that have formed overtime due to normal use of your vehicle.  They can also help remove scale and precipitation caused when your vehicle recently over heated.  Since you already are draining your vehicle’s cooling system to replace the thermostat, you are only adding 2 extra steps to your project, adding BlueDevil Radiator Flush and driving for a few days, then draining the system again.  For more information on how easy it is to use BlueDevil Radiator Flush you can find the directions online here..


You can also purchase BlueDevil Radiator Flush at any of our partnering local auto parts stores like:

  • AutoZone
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributer
  • DYK Automotive


Picture provided by:

Car Thermostat – By Hoikka1 in Own Work.  Licensed under Creative Commons Share Alike 3.0 Via Wikimedia. Original Link

Related Posts

31 responses to “Do I need to Change My Car Thermostat?

    1. Leiatra-

      The labor cost on replacing the thermostat varies greatly between different types of vehicles. On some cars it is a very quick job where other vehicles will require additional parts to be removed to access the thermostat.

      Thank You!


      1. I bought a used car (Toyota Corolla) from the US and i’m in Sierra Leone.I’m advised to remove the thermostat because of our weather condition.Pls,advise.Thanks.

        1. Abioseh-

          Thank you for asking about your Toyota Corolla. Having the thermostat removed from your vehicle will create a free-flow in the cooling system. It would give you better circulation and help the vehicle from overheating, which is not a bad idea when residing in warmer climates. Feel free to contact our technical support line at 888-863-0426 with any other questions.

          Thank you!


  1. I am moving from New Jersey to Texas & have a 2010 VW. Do I need to change to a different thermostat fro a for warmer climate? If so, what is such thermostat called?


  2. I have a 2012 Sportage of which my thermostat was removed due to not opening properly. My A.C Tech said that it was not needed since I live in the Bahamas were it is constantly warm/hot weather. Should I keep the thermostat out or have a new one placed in?

    1. Aya-

      You would be fine to leave the thermostat out of your Kia Sportage, being that you live in a warmer climate. You would really only run into an issue if you needed heat in the car. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!


  3. My car over heated due to radiator leak and an engine code came on. I fixed the coolant leak, cleared the code. The car runs great now and doesn’t overheat. The thermostat seems to be operating fine. Should I replace it anyway?

    1. Michael,

      Thanks for your question about your vehicle’s thermostat. If your temperature gauge shows normal operation of your thermostat then you most likely haven’t damaged it. You may consider watching it closely for the next few hundred miles, especially when going up hills or putting a lot of load on the engine as the most common thing a broken thermostat does is not fully open restricting coolant flow which can cause overheating at high loads.

      Thanks again for your question!
      -BD Auto Pro

  4. I was told that I need to replace my thermostat and gasket if I am driving one way from California to Ohio next week. I have a 2004 Nissan Altima. Do I need to do this to do this now in order to prevent the engine overheating or can it wait til I get to Ohio?

    1. Shoshanah-

      Thank you for asking about your Nissan Altima. Based on your description, we’d recommend changing the thermostat before making your trip. A faulty thermostat could cause the engine to overheat during your trip, which could lead to other issues such as a blown head gasket.

      Thank you!


  5. I am replacing my radiator and both hoses car runs cool never above 1/3 on the dail would suggest to go ahead and put new one in or just leave the current one in thanks
    1999 honda accord lx 4 cylinder automatic

    1. John-

      Thank you for asking about your Honda Accord. Based on your description, we would recommend replacing the thermostat when you replace your radiator and hoses. It’s better to be safe than sorry. A faulty thermostat could restrict the circulation of water/coolant in the system and cause the vehicle to overheat, leading to an array of problems. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!


  6. I have a 2006 gmc envoy,,, my check engine light comes on and stays sometimes for weeks… have not noticed any overheating or raise in temp… I dont drive alot… I am taking a trip from oregon to cali and was told to replace my thermastat… I have quotes from 179.00 to 400.00 why such a jump….

    1. Deborah-

      Thank you for asking about your GMC Envoy. Thermostat replacement for your vehicle can range from $104-$174 on average. Was there any additional work that needed to be done? We recommend shopping around for a reputable mechanic to do the work at a reasonable price.

      Thank you!


  7. hi, I am confused about this Thermostat. I checked it out on the internet, and some are saying I shouldn’t removed and you are also telling me is good to remove it. I live in Africa, Liberia and trying to get a Nissan primers P11.plz advise me. thx you, Salim C. Jabateh

    1. Salim-

      In terms of using the BlueDevil Head Gasket Sealer (32 oz. yellow label), removing the thermostat is a required step in completing the process. It is not necessary to remove the thermostat for normal vehicle use, unless you plan on replacing it.

      Hope this helps!


  8. Hello, i have a 05 sebring, and currently the check engine light is on.
    I checked with my OBD tester and showing cooling thermostat problem.
    When i am driving, my car engine temperature won’t go up quickly. sometimes it stays around the middle,
    sometimes very low, around quarter area.
    Do i need to change my thermostat? my mechanic says i dont need to, but i am just very concerned
    since the engine temperature goes stays up and down.

    1. David-

      Thank you for asking about your Chrysler Sebring. Based on your description, we recommend changing the thermostat in your vehicle. A faulty thermostat can give you false temperature readings and could also cause further issues down the line. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!


  9. The heat in my car is not working, could this indicate a problem with the thermostats? (I have 2 in my 2011 avenger). Is there any reason thermostats may need to be replaced for this reason or to perform a heater core flush?

    1. Jen,

      Thanks for your question about your Avenger. If your ventilation fan is blowing and it’s only blowing cold air, there could be a few things causing the problem. First, it could be that you’ve got a failed thermostat. If that is the case, the temperature gauge in your car would also read abnormally low not allowing your car to heat up. Also, you’re on the right track that your heater core could be in need of a flush. If the core is clogged or blocked it could be causing your heat not to work. Since your car is relatively new, that seems unlikely that it would be that blocked, but it wouldn’t hurt to flush your cooling system.

      The other problem could be with your ventilation system. There is a door in the air ducts that moves to direct air over your heater core if you turn the heat on, or around it if you have the temperature control set to cold. If that door is broken or stuck in the “cold” position it would also make your heat blow cold from the vents.

      Thanks again for your question!
      -BD Auto Pro

  10. I live in Rhode Island and work at home, so I don’t put a lot of miles on my car these days. I had my Thermostat and gasket replaced in my 2009 Hyundai Accent in November of 2015. I just took it in for regular maintenance in Dec 2016 and was told I needed to replace the Thermostat and gasket again. I had it done, but am wondering how often this needs to be done?

    1. Andrea-

      Thank you for asking about your Hyundai Accent. You really shouldn’t need to replace the thermostat unless you notice that it is not working properly. Typically, you can change the thermostat when you replace your radiator or heater hoses.

      Thank you!


  11. My car produces a burnt rubber smell particularly when it is stopped and this is enhanced when the heat is on. My mechanic told me that I need to replace my thermostat, however it shows a perfectly normal temperature gauge- no overheating at all. He said it may be stuck open. Should I trust him? Thanks!

    1. Jessica-

      Based on your description, it is difficult to say that a faulty thermostat is the cause of the burnt rubber smell you are getting. It is possible one of your hoses may have come loose and landed on a hot part of the engine. Whether that is the case or not, changing the thermostat would not correct that issue. You may want to bring the vehicle in for a second opinion.

      Thank you!


  12. I have a 2008 volvo, and have a leak in the radiator hose. Engline light came on saying low coolant, stop engine. They tell me I need to replace thermostat. The car has never over heated. Is this necessary?

    1. Coreen-

      Thank you for asking about your Volvo. It is possible that the thermostat is not functioning properly, causing the cooling system to have poor circulation, and not allowing cooling to flow through the system as it should. After replacing the radiator hose, it would be a good idea to replace the thermostat as well.

      Thank you!


  13. The job of thermostat in a car is to stop the flow of coolant to the radiator until its engine gets warmed up. When the engine becomes cold, there is no flow of coolant through the engine and when it reaches the operating temperature about 95 degrees Celsius, the thermostat is opened up. So, like other parts of the car, thermostats have to be maintained regularly. You should consult with a professional to check whether there is an issue related to the part, otherwise it may let you to face problems in future.

  14. I found out very recently that my radiator was leaking coolant when my car (almost) overheated several times on a drive home. The gauge reached about 3/4, but never hit the red zone. I’ve been monitoring my temperature gauge and my coolant level, topping off when necessary to compensate for the leak and buy myself a few days before repairs can be done. The temperature gauge has remained at normal operating 1/2, even on steep inclines, since I’ve starting topping off the coolant. I’ve been getting quotes from various highly rated mechanics to find the best deal for repairs, since money is tight. One mechanic recommended I get both hoses and the thermostat replaced with the radiator. Is it necessary to replace the thermostat if it appears to still be in good working order? Is it a costly risk to take to not have it replaced?

    1. Max-

      It may not be 100% necessary to replace the thermostat in this case, however, it would be recommended. The thermostat is one of the least expensive parts to replace and often can be the cause of overheating issues or the original cause of the leak, so it makes sense replacing it when the radiator is replaced to ensure it doesn’t cause the new radiator to develop a leak.

      Thank you!


Leave a Reply

Your email address will not be published. Required fields are marked *