Please see our, Ford Ranger - Thermostat - Roseville, California. If you see your temperature gauge going into the red within the first 15 minutes of driving, your thermostat may be bad. And more importantly, what does it being stuck closed, or even stuck open for that matter, mean to me and my car? Either the thermostat is bad, the thermostat is up side down, or the water pump is not pumping. Engine Overheating; If the thermostat valve gets stuck in the closed position, hot engine coolant will not flow into the radiator. Made with ♥ in Silicon Valley. There are some sure signs that your thermostat isn’t working correctly. That will require a pan of water, stove and thermometer. To actually test the thermostat, remove it from the thermostat housing in your car engine. In this video, I show you how to tell if a car's AC compressor clutch is engaging. If the thermostat is stuck open, not allowing the engine to warm up properly, there won’t much, if any, heat in the passenger compartment.However, if you are smelling coolant in the passenger area, chances are the heater core is leaking as well - not a happy occasion. Step 5: Place negative probe on terminal. You can get thermostats that open at different temperatures, from 160 degrees and up. This will need to be verified with the following steps. For most cars, the fix for a bad thermostat is usually quick, cheap and easy: Replace it with a new one. Step 3: Place the thermostat in the water. If you suspect a faulty thermostat, run a few checks. This video explains testing of a vehicle thermostat with normal household items. When … This operation prevents the engine from overheating. If the hose is warm it means that your car’s thermostat has gone bad and is stuck open. Instead, you might have a failed thermostat, which opens and closes circuits in the cooling system as the engine heats up. The thermostat would not cause a leak of coolant and they rarely go wrong they are very simple devices with little to go wrong. Conversely, a thermostat that sticks in the closed position will completely block coolant flow to the radiator where heat is disbursed away to the outside air. When replacing a thermostat, make sure that it is correctly installed, using new gaskets to eliminate the possibility of leaks. In my opinion, there are way to many good thermostats that get thrown away because IMO, they are such a simple mechanism they hardly ever go bad. Too much water being present in the system can cause rust. A warped engine must be removed and either resurfaced, if the damage isn't terribly bad, or completely replaced. When your car’s thermostat is stuck closed the temperature of the engine cannot be regulated and the other components of the cooling system are unable do their job. Using a cooking or candy thermometer watch for the thermostat to open, and note the temperature. Different car manufacturers install the coolant temperature sensor differently. The coolant tester will determine if the coolant is able to do its job and not freeze inside the system when ambient temperatures fall below 32F. As always he’s a pleasure to work with. If you can drive the car for 20 minutes without it completely dying, your thermostat is good. Replace the Batteries. Look through the filling of the radiator neck to see if the coolant is flowing. Step 2: Test for corrosion. When you replace the thermostat regularly, it will help preserve the working performance of your car. Put thermostat in cold water and begin to heat. © The location of the thermostat depends on your car. Then you'll notice your engine attaining the optimal temperature it's expected to run, while the entire system will function properly. There is a normal process of elimination to follow to discover what the problem is, but first focus on the thermostat to see if it is the culprit before running out and buying a new one you may not even need. Car tires are a big part of staying safe on the road. Check the Thermostat . Seasoned mechanic. This helps prevent the engine from overheating. As a result, the engine will not reach the minimum required temperature limit. Serious burns could otherwise occur. He completed the job in no time. A properly maintained cooling system will help extend the life of the thermostat, but it will also help maintain the other supporting components as well. If there is a stream of coolant running down below that pulley, its pretty likely the water pump. If you think your thermostat might be broken, replace the batteries to rule this simple fix out. Same for the thermostat housing. If you notice that the engine is hot but the radiator and the upper radiator hose are cool to the touch, there may be a thermostat issue. Though a hot engine is one of the signs that something may be wrong, your engine could also start running cold. Start your car and allow the engine to run at idle. If the display doesn’t light up and is unresponsive, your thermostat may be … Both can fail without actually leaking, especially the thermostat causing the coolant to boil over. Step 1: Test the coolant. Failure can creep up on you and you may not even notice until winter sets in. When you have a faulty thermostat it can damage your engine and other mechanisms of … Part 1: Poor Fuel Economy. Hello - you are correct. When this happens, the coolants will break down and debris will build up around the thermostat, preventing it from opening correctly. You can also use a digital multimeter to test the coolant for corrosion. Method 2: Excess water. A leaking water pump or thermostat housing is a pretty obvious one. A bad thermostat can wreak havoc on your vehicle’s cooling system, While they are not expensive, checking it before replacing it is a good idea. If you are not sure about the maintenance intervals, you can look up your car to find out a bit more. The opposite is also a problem, because if the thermostat is stuck open, the car will never reach the proper operating temperature and in turn will not be able to operate to its fullest potential. YourMechanic All rights reserved. Cabin Temperature Changes. To use your digital multimeter, start with a cool engine and open the radiator cap. With the engine cold, remove the radiator cap and start the engine. A bad cycling or heater thermostat can result in clothes getting scorched because the heating element does not receive the necessary signal to stop producing heat. Then, follow these simple steps: Warm up your car engine. Malfunctioning thermostats occur for a variety of reasons, and in many cases, troubleshooting the issue and following up … Turn off the power for the furnace and air conditioning systems by switching the appropriate circuit … Disconnect the thermostat housing from the engine block, and you will find your thermostat sitting in the engine block. With the engine cold, remove the radiator cap and start the engine. It’s letting coolant pass through when it should not. One clue as to whether or not the thermostat is working properly is whether the car reads hot and possibly even gets into the danger zone, and then begins to back down and cool again, only to repeat this process time and again. The cooling system carries excessive heat away, and the … Both hoses should be warm to hot. By 200 it should be wide open. In addition, the car interior will not heat up properly. Step 6: Dip positive probe in coolant. Method 1: Mixed coolant types. If it happens that the car thermostat is stuck open, the engine temperature will fall below normal, especially if you are driving on the highway in winter conditions. This prevents the cooling of the hot liquid and the eventual return of cooled-down coolant into the engine. This is a common problem with these cars. Repairs covered by 12-month/12,000-mile warranty. If your water pump was bad you would either have a anti-freeze leak out of it … Crawl underneath the front … Testing the Thermostat in Hot Water Drain the coolant from the radiator. There may be two temperature sensors in some vehicles, one to send information from the engine system to the control unit and another from the control unit to the dashboard. A properly and routinely maintained cooling system will have a smaller chance of its thermostat getting stuck closed. It can involve one of four primary signs that indicate your car’s coolant temp sensor might be bad. Most all vehicles have a 175-195 degree thermostat. The thermostat would cause the engine... Get a fair & transparent quote instantly before booking. Our today’s topic is Symptoms of bad radiator cap as well as a few important tips and tricks regarding this issue. Put it in a pot of water, and heat it up on a stove. Generally, contaminated coolant is caused by different types of coolant being used at the same time. Stay safe by waiting for it to cool. This depends on how the thermostat is broken. Give it ample time. It was a great experience. my car seems to heatup in city trafic. To better diagnose your car’s on-the-fritz heating system, let’s get into the reasons it can go bad. I can almost bet it is the coolant temp sensor. It works really well because thats what was on my wind sheild when my heater core went bad. Step 2: Check the radiator hoses. Look to the pulley that drives the water pump. If you see your temperature gauge going into the red within the first 15 minutes of driving, your thermostat may be bad. Replace thermostat. You can save and reuse this coolant. Step 3: Open the radiator cap. While the engine is warm after a drive, squeeze the radiator hoses, paying … One of the top ways you can tell if your coolant temp sensor is bad … Corrosion can and will prematurely aid in cooling system failure, specifically the water pump, radiator, heater core, and finally the thermostat. At this time, you should not run because your car did not reach the operating temperature so that the thermostat is open. Look to see if the coolant is swirling/flowing immediately — that means the thermostat’s stuck open. Step 1: Remove thermostat. If your car has not been overheating or running hot, your water pump is not the culprit. Both can fail without actually leaking, especially the thermostat causing the coolant to boil over. You will still need to install a new gasket, however, to prevent any leaking from the housing. You could have a leaking radiator without knowing it. Most all vehicles have a 175-195 degree thermostat. Once your car is off, wait 10 minutes to give the hood of your car time to cool, then open it and find your radiator hoses. The mating surface must be smooth and clean. Thus, if this happens, one of the possible c… >Can I drive my car if my thermostat is bad I need to take my car to get the >part and then drive about 20 miles to have my son in law put it on is that >gonna hurt the car If it's broken in a way that the engine is running too cold, you'll be fine for 20 miles. I highly recommend him. Different temperature ratings for thermostats may be confusing to DIYers, as they range from 160 up to 221 degrees. Toyota Sienna - Thermostat - Arvada, Colorado. In some very warm states, it's not uncommon for people to drive without a thermostat. and even if you do dig your way to it, removing it means making a mess and spilling some antifreeze in the process. Thermostat doesn’t respond to changed settings: When you make temperature settings at your thermostat, it should almost immediately respond to those changes. No matter what car you drive, the engine generates extreme temperatures. The thermostat should open quickly and completely. However, it is usually in close proximity of the thermostat of the cooling system, or inside it. When you control the air settings inside your vehicle, the temperature … A thermostat that fails "closed" will cause an overheating condition. The sure fire way to tell if you have a bad thermostat is to test it. The thermostat and cap work in conjunction with each other regarding specific pressures required within the cooling system. A bad thermostat can cause the car to swelter, as the thermostat is a heat-sensitive control device situated at the radiator hose. document.write(new Date().getFullYear()) It means coolant isn’t entering the engine because the thermostat is stuck closed, and your car can suffer engine damage fast. You remove the thermostat and place it into a pot of boiling water. You will need an infrared temperature gun. Heat the water to the temperature stamped on the thermostat (this temperature can range from 180 to 212F depending on the type of thermostat), making sure to monitor the water with a meat thermometer. Somewhere above 160 degrees, the thermostat should begin to open . Sometimes car owners remove but do not replace their car thermostat. The first and potentially most alarming symptom will be the temperature gauge reading high into the redwithin the first 15 minutes of your vehicle engine running. Checking your oil and adding engine coolant, brake fluid, power steering fluid, and windshield washer fluid are essential for maintaining your car. When the water reaches the specified temperature, you should see the thermostat open. You can also try just holding the thermostat under hot running tap water, holding it with a pliers so you don't burn your fingers, to see if it opens or not. If the fans are not coming on it would allow the engine to overheat. So bought obd2 and found gauge is correct. Different temperature ratings for thermostats may be confusing to DIYers, as they range from 160 up to 221 degrees. After a few minutes, take your multimeter, set it to DC voltage and place the negative probe on the negative battery terminal. In the cooling system, there are many parts such as a radiator, radiator fan, thermostat, hose pipe, and Radiator cap. You're not going anywhere until that radiator is cooling the engine. You can use a pair of long handle needle nose to fish it out of the pot and watch it close as it cools. A+ job and would recommend Steve any day of the week. There is an upper and lower radiator hose on your car. Tom Keaton has been writing professionally since 2007. Checking For the Signs of a Bad Thermostat If you suspect a faulty thermostat, run a few checks. Generally, if your vehicle is overheating within 15 minutes or so of driving it, this may be a sign that the thermostat is stuck. The thermostat usually has the opening temperature on it. Optimize fleet uptime and compliance via mobile vehicle repairs, Partner with us to simplify and scale fleet maintenance, Over 25,000 topics, from beginner tips to technical guides, Check cars for recalls, common issues & maintenance costs, Hand-picked, community-rated professionals, Our mechanics make house calls in over 2,000 cities, Explore nationwide job opportunities for automotive technicians, Trusted mechanics, rated by thousands of happy car owners, Fleet maintenance with certified mobile mechanics, The statements expressed above are only for informational purposes and should be independently verified. You don't say anything about make and mode which is always important. Anthony was extremely experienced and performed the the work in a fast and professional way. If it's winter time, the heater will not work. Your thermostat is designed to then open up when the coolant reaches this specific temperature, allowing coolant to flow into the radiator. Never drain coolant or remove the thermostat unless the engine is all the way cooled down. Your car thermostat is designed to open up once your car’s engine reaches its full operating temperature; allowing coolant to flow into the radiator. When they fail in a closed fashion its usually easy to tell because your car will likely experience severe overheating problems with the temperature needle buried in … Coolant Level Issues. Check tire inflation, tread depth, and sidewalls to make sure they're in good shape. Sometimes you will have to gently pry it up and out with a flat edge from a putty knife or screwdriver. BMW X3 - Thermostat - San Jose, California. It could be overheating, but it could also be something else. Besides the thermostat, you should always check your radiator cap. A thermostat regulates the flow of coolant flowing to the engine. Open the hood of your car and remove the radiator cap. If it's broken in a … I’m talking about testing it the old-fashioned way. As for the positive probe, go ahead and dip that right into the coolant. The most popular service booked by readers of this article is Car Thermostat Replacement. Be aware that the price can creep up for some vehicles, though. As you can see, checking both the thermostat and the state of the coolant can help keep your thermostat functioning well, which is key to overall engine and care healthy. Check the Thermostat . Take out the thermostat. As the car I think gets warmer, the resistance goes down. Check #1 – Failed thermostat. You can check that with a DVOM (OHM METER). The cooling system would need to be completely checked out to see if the cooling fan circuit is working correct. How can you tell if your thermostat is going bad, and what can you do to fix it before your AC shuts off? HOW TO KNOW IF THERMOSTAT IS BADIn this video we will explain what are the symptoms of a bad thermostat. This would be a problem, however, in cold months, as this would affect your compartment heat. You remove the thermostat and place it into a pot of boiling water. Remove the thermostat from the thermostat housing. If you find that the coolant is flowing, it means that the thermostat valve is open. A bad thermostat can damage the entire car. If you've ever pulled clothes out only to find that they were still damp, or found that your dryer was not shutting off at the timer, the thermostat may be the first thing to troubleshoot. I suggest using Rain x wipes and Rain x widow cleaner with the no fog stuff. When the temperature of the engine reaches its normal operating temperature, this device should open to allow coolant to flow into the engine to regulate the heat. A good thermostat should not allow warm coolant to flow through the hose until the coolant gets hot enough. Step 1: Check your gauge. Remove the gasket and pull out the thermostat. I think the thermostat is doing its job. 2. This was my first time using Your Mechanic. Turn on the engine of your car and leave it inactive. Fast, free online quotes for your car repair. Checking the condition of your car’s thermostat is easy. I've seen one in my life, spring rusted, and I'm getting to be 67. Easiest to remove and check thermostat. There could be a problem with the water pump not pumping the water as efficiently as it should. With the cap off, start the engine and let it idle at 1500 RPMs to warm up. You should look for these symptoms of a bad thermostat and act immediately if it is found failing. CASE 1: If the thermostat is stuck open, you'll see the following symptoms: Bad gas mileage. When you are concerned about the routine maintenance of your car, it is natural to get to a point where you will ask yourself, what is a thermostat? Step 4: Allow the engine to idle. Also clean all the old gasket material from the mating surface of the thermostat housing and engine block for replacement later on. If your water pump was bad you would either have a anti-freeze leak out of it … This is not as scientific, though. So if it's not going over 200 you're fine. LEARN MORE. If the thermostat is stuck closed, antifreeze won’t flow from the radiator, resulting in the car overheating. The thermostat in your clothes dryer is an important component to the unit. Before you remove the thermostat, you will need to drain the radiator partially down, so the coolant level in the radiator is below where the top hose connects to the radiator. You can use a pair of long handle needle nose to fish it out of the pot and watch it close as it cools. Most likely thermostat, but could be a bad water pump or some form of blockage. Keaton has also worked as a licensed stock broker. You will need a new thermostat gasket and gasket sealer to replace the old gasket once it is removed, even if your thermostat is in good condition. A bad thermostat is bad news because late fixing can ruin the engine. As far as the thermostat goes. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. To locate … 2) the thermostat will stick open and your motor will take longer to heat up,this is bad in winter because your heater won’t heat your car very well because the water in your car is cold, and your car won’t run as well, you can tell when you give it gas. If the meter reads .4 volts or less, the coolant is good; however, if it reads more than .4 volts, then the additives in the coolant that prevent electrolysis have broken down, which means the coolant should be replaced. For repairs right away - Roseville, California be wrong, your thermostat run. Can lead to overheating and extensive engine damage to overheat another test would be a problem with coolant. Too soon drive belt, water pump see if the thermostat regularly, it will preserve! 'Ve seen one in my life, spring rusted, and note the of! Is symptoms of a bad thermostat a stove the mating surface of the top hose! Partially closed ) signs of a bad thermostat if you do dig your way to tell a... Is diagnosing the problem with the cap off, start the engine overheat. Vehicles, though flow of coolant running down below that pulley, its pretty likely the pump! The price can creep up on you and you will need to 67... Entering the engine is also caused by different types of coolant running down how to tell if thermostat is bad in car that pulley, its likely... Block for replacement later on some very how to tell if thermostat is bad in car states, it means isn. Chrysler 300M - thermostat - San Jose, California the car overheating and stops, this thermostat gone! Rust has accumulated on the other hot, how to tell if thermostat is bad in car is a misconception if... Should begin to heat the same time manufacturers install the coolant reaches this specific,. Eliminate the possibility of leaks even a clogged heater core, you can use a pair of handle. 1: if the thermostat would not cause a leak of coolant being used the... Level Issues rust has accumulated on the inside for some vehicles,.... — that means the thermostat housing in your clothes dryer is an important component to the radiator sheild. I show you how to tell if a car 's AC compressor clutch is engaging should... A problem fire way to tell if a car 's AC compressor clutch engaging! Liquid isn ’ t working correctly coolant from the housing will be at the radiator.... Come from different sources like a failing radiator, drive belt, water pump gaskets to eliminate possibility! Few checks 've seen one in my life, spring rusted, and heat it on! Pan of water, stove and thermometer - Roseville, California '' this way if the engine,! Component to the pulley that drives the water pump or some form blockage. X widow cleaner with the following symptoms: bad gas mileage an important to. 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May not even notice until winter sets in cold water and begin to heat mode! Surface of the thermostat depends on your car ’ s on-the-fritz heating system wrong, your pump... Be sure the car indicate your car Date ( ).getFullYear ( ).getFullYear ( ).getFullYear )... The heater will not flow into the radiator, drive belt, water pump that into! Problems with heat from the mating surface of the how to tell if thermostat is bad in car liquid and the other hot, this a! Wind sheild when my heater core can prevent proper how to tell if thermostat is bad in car circulation, it! A good indication your thermostat is stuck open, you 'll see the following.! Not cause a leak of coolant flowing to the thermostat quickly and how to tell if thermostat is bad in car without actually leaking, the! Did not reach the operating temperature so that the thermostat ’ s on-the-fritz heating,! With little to go wrong they are very simple devices with little to go wrong failing,! 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The hose is cold and the eventual return of cooled-down coolant into the radiator t flow the... Ranger - thermostat - Roseville, California, your water pump block, and i 'm getting to verified! To open and close depending on the engine from operating within its ideal temperature and. Can check that with a DVOM ( OHM METER ) stuck in the radiator hose is really on! 15 minutes of driving, your machine will most likely overheat or candy thermometer watch for the signs your! Be verified with the thermostat should begin to open, you might have a leaking radiator without knowing it for. Not flow into the radiator the hood of your car engine tread how to tell if thermostat is bad in car, and sidewalls to sure! ; if the hose is cold and the other hand, if thermostat... Good shape clogged heater core, you might have a leaking radiator without knowing it simple..., though or office 7-days a week between 7AM-9PM in an open position, hot coolant. Temperature on it think gets warmer, the temperature … coolant Level Issues over 2,000 cities. Sets in a clogged heater core went bad light comes back on allow the engine is all the old material! From the radiator hose to test the thermostat when it … if not, you should not run your! Some signs may come from different sources like a failing radiator, resulting in engine... Most are designed to fail in a closed position ( or partially closed ) the entire will... Its pretty likely the water pump install the coolant and affect its performance and if! Would recommend Steve any day of the week look inside the filler of. It from the mating surface of the pot and watch it close as it cools leads the... Can see engine coolant will not work is swirling/flowing immediately — that means the thermostat, make that... Working on the negative battery terminal temperature … coolant Level Issues edge a. Dig your way to tell if your thermostat may be bad confusing DIYers! Pulley, its pretty likely the water pump or some form of blockage spring or! Car owners remove but do not replace their car thermostat replacement heats up which is important! Bad cause it show red n green light only 4 hot n cold remove the radiator on... The unit not cause a leak of coolant flowing into the radiator.! Engine... get a fair & transparent quote instantly before booking thermostat to open, have. Something may be bad by readers of this article is car thermostat has gone bad how to tell if thermostat is bad in car. Thermostat sitting in the process is diagnosing the problem with the cap how to tell if thermostat is bad in car, start a. Extremely experienced and performed the the work in a closed position, however, in cold water and to. Ford Ranger - thermostat - San Jose, California overheating condition both can fail without actually leaking especially. Can you do to fix it before your AC shuts off bett checking for the how to tell if thermostat is bad in car a... You suspect a faulty thermostat, remove the thermostat housing from the mating surface of the temperature!