Full Video : H0409037_What Happens When You Punch A Cop

How to Decide Whether to Replace Your Car’s Thermostat in 2026: An Expert’s Guide By Rick Cotta Updated: January 11, 2026 Share should i change thermostat jpg Car thermostat | Cars.com illustration by Angela Anderson Key Points A car’s thermostat typically requires replacement only if it fails. Symptoms of a faulty thermostat include the car’s engine not warming up enough to run properly and generate heat in the cabin, triggering the check-engine light or the engine overheating. Thermostats can sometimes be replaced without assistance, but more complex systems in modern cars can require a mechanic. As important as it is to the proper operation of your car, the thermostat is not typically replaced merely as a maintenance item; it’s usually done only if it’s determined to be faulty. That’s because a thermostat often lasts a long time — sometimes the entire life of your car. An exception might be if the car has high mileage and related parts have to be replaced, such as the water pump, radiator or radiator hoses. Replacing those parts often covers most of the expense of replacing the thermostat; as such, adding the small cost of the thermostat itself might improve peace of mind as it may ward off a problem down the road. In this 2026 guide, we’ll dive deep into whether you should consider changing your thermostat, the signs of a failing unit, and what this could mean for your car’s performance and your wallet. As a mechanic with over a decade of experience in automotive repair and diagnostics, I’ve seen countless vehicles come through the shop with thermostat issues — and I’ve helped hundreds of owners make the right call. Related: Why Does My Car Heater Blow Cold Air? What Does a Car’s Thermostat Do? Takeaway: A car’s thermostat opens and closes based on the coolant’s temperature to route coolant through the engine, radiator and heater core. The thermostat is a valve in a car’s cooling system that opens and closes based on the temperature of the coolant. When the engine is cold, the thermostat is closed, which forces the coolant to circulate only throughout the engine, allowing the coolant and engine to warm up faster. Once the coolant reaches the low end of the car’s normal operating temperature, the thermostat begins to open, routing coolant through the radiator hoses to the radiator. At this point, coolant also routes to the heater core, which can then begin heating the interior of the car. Note that figures vary from car to car, but the general range for what’s referred to as “normal operating temperature” is approximately 180-200 degrees Fahrenheit. Circulating the coolant through the radiator keeps the coolant from getting too hot, which would make the engine overheat. Warning Signs of a Failed Thermostat Takeaway: A faulty thermostat may trigger the check-engine light to illuminate or cause the engine to either not warm up or overheat. If it fails, the thermostat usually either sticks open or closed. (It can also leak coolant at its gasket mating surfaces, but that’s not really the fault of the thermostat.) If it sticks open, the coolant — even when cold — circulates through the radiator, preventing the coolant from warming up quickly, if at all. This also keeps the engine from warming up and running properly, and that sometimes sets off the check-engine light. In cold weather, it also doesn’t provide much heat for the cabin since the heater relies on warm engine coolant to produce heat. Worse, however, is if the thermostat sticks closed. That prevents the coolant from circulating through the radiator once the coolant gets warm, making it get hotter and eventually causing the engine to overheat. Most cars have a coolant temperature gauge, but some just have a warning light, which usually either says “Temp” or has an illustration of a thermometer sticking out of wavy lines representing water. The gauge’s needle may sit at around midway through its range when the engine and coolant have reached normal operating temperature. With a light, the light might illuminate when the engine and coolant are still relatively cold, indicating you shouldn’t drive fast yet; the light will turn off as the coolant approaches normal operating temperature. If the light goes on after driving for a spell, it usually means the engine is overheating, so the light may be on when the engine is either too hot or too cold. Read More Car Maintenance Tips: What Is an EGR Valve and What Does It Do? Why Does My Car Squeal When I Turn the Steering Wheel? Do You Need to Change Your Car’s Power-Steering Fluid? How Much Oil Consumption Is ‘Normal’? More Car Maintenance News Replacing a Thermostat Takeaway: Some thermostats can be easy to replace, but some newer car models may have complex computer-controlled thermostats that require a mechanic. While most thermostats are simple, inexpensive devices, some late-model vehicles have more complex computer-controlled thermostats that are also more expensive. Similarly, most thermostats are fairly simple to get to, while others are tucked away, requiring many components to be removed first to change them. A simple thermostat that’s easy to reach doesn’t cost much to replace, and you can often do it yourself. On the other hand, a computer-controlled thermostat that’s difficult to access should be done at a shop and can cost several hundred dollars. To get an idea of what kind of thermostat you have and where it’s located, follow the upper radiator hose from the radiator to the engine. The thermostat is usually located where the hose meets the engine. If that’s easy to see near the top of the engine and there are no wires going to it, you’re in luck; however, if the hose disappears into the darkness of the engine bay or you see wires going to where it meets the engine, the replacement cost will be higher. An alternative is to do an internet search for something like, “How do you replace the thermostat on a [year/make/model] (e.g., 2012 Toyota Camry with a 3.5-liter V-6)?” If you can find a video demonstrating the process, that should give you an idea of what you — or your mechanic — will encounter when it’s time to change the thermostat. Related Video:\n\n\nCars.com’s Editorial department is your source for automotive news and reviews. In line with Cars.com’s long-standing ethics policy, editors and reviewers don’t accept gifts or free trips from automakers. The Editorial department is independent of Cars.com’s advertising, sales and sponsored content departments.\n\n## Your Guide to Thermostat Replacement in 2026: Is It Time to Replace Your Car’s Thermostat?\n\nIn the competitive landscape of automotive maintenance for 2026, decisions often come down to cost versus long-term value. As a mechanic who has spent over a decade diagnosing and repairing vehicles, I can confidently say that the question, “Should I change the thermostat in my car?” is one of the most common—and most important—questions a car owner can ask. This isn’t just about a simple part replacement; it’s about understanding your car’s health and making smart financial decisions that protect your investment.\n\n### Understanding the Thermostat’s Role in Modern Vehicles\n\nBefore we dive into the decision-making process, let’s clarify what the thermostat does. Think of it as the gatekeeper of your engine’s temperature. It’s a mechanical valve that opens and closes based on the coolant’s temperature, controlling the flow of coolant between the engine and the radiator. When your engine is cold, the thermostat stays closed, allowing the engine to warm up quickly. Once it reaches the optimal operating temperature, typically around 180-200 degrees Fahrenheit, it opens, allowing coolant to circulate through the radiator and maintain that temperature.\n\nIn 2026, cars are more sophisticated than ever, with complex computer systems constantly monitoring engine performance. This sophistication means that a faulty thermostat doesn’t just cause a minor inconvenience; it can trigger a cascade of issues that impact fuel efficiency, emissions, and even the longevity of your engine. Understanding these dynamics is crucial for any car owner looking to maintain their vehicle’s value in the current market.\n\n### Common Symptoms of a Failing Thermostat in 2026\n\nIdentifying the signs of a failing thermostat is the first step in determining whether a replacement is necessary. As a mechanic, I’ve seen these symptoms manifest in various ways, from subtle performance issues to critical failures that can leave drivers stranded. Here are the key indicators to watch out for:\n\n1. Engine Not Reaching Optimal Temperature: This is one of the most common signs of a thermostat stuck open. If your car’s temperature gauge consistently reads below the normal operating range, or if your heater blows cold air even when the engine is running, it’s likely that the thermostat isn’t opening properly. In 2026, with the emphasis on fuel efficiency, this can have a significant impact on your gas mileage, as the engine isn’t operating at peak efficiency.\n\n2. Engine Overheating: A thermostat stuck closed is a recipe for disaster. When the thermostat fails to open, coolant can’t circulate through the radiator, leading to rapid overheating. This can cause severe engine damage, including warped cylinder heads and blown head gaskets, which are costly repairs. In today’s market, where replacement car prices are at an all-time high, protecting your engine from catastrophic failure is a top priority.\n\n3. Check Engine Light Illumination: Modern vehicles are equipped with sophisticated diagnostic systems that monitor