How Do You Know If Your Thermostat In Your Car Is Going Bad?


4 Answers

Elizabeth Leake Profile
Elizabeth Leake answered
There are a few ways to tell if a car thermostat is bad. Keep an eye on the thermostat when it starts moving up. Does it climb to a very high temperature and then decrease?

If the thermostat does not start decreasing until it has reached the danger zone, then the thermostat may be faulty, The reason for this is because at a certain heat (which will vary for each car) the thermostat should open, causing the engine to cool down. However, the thermostat should not allow the car to reach danger level as this can cause the engine to overheat and damage the mechanisms and much more.

  • Test
One way to test whether your thermostat is working properly is to turn your ignition off and wait for the engine to cool down. Once cooled, start the engine and open the bonnet. There will be two pipes, as you leave the engine running one pipe should stay cool and the other warm up. The cool pipe should only change temperature once the thermostat has opened. If this is not the case then it sounds like you may have a faulty thermostat.

  • Replacements
Do not worry though, as thermostats are not that expensive to replace compared to many other parts It is a good idea to get it replaced as soon as you realize it is faulty, as it can cause more damage to the car and end up costing you more money the longer you leave it.
Daniel Hellard Profile
Daniel Hellard answered
More than likely, yes. First make sure your antifreeze is full. Otherwise take your car to a mechanic. Unless you know how to take your thermostat out. If you do, then take it out and put it in a pot of almost boiling water. If you see it open up, then it's fine. If not, you need to replace it.
Eric Ackerman Profile
Eric Ackerman answered
You can pull the thermostat off the vehicle and put it in boiling water, if the valve closes the thermostat is good, if it doesn't close it is bad. What this does is simulates a vehicle reaching its hot point, and telling the thermostat to open up to allow the coolent to flow.
Anonymous Profile
Anonymous answered
Put it in a boiling vegetable oil. If it opens, good. If not replace it.

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