What Causes A Thermostat To Go Bad?

Do you know what your thermostat does for your engine? This is a tiny piece in your engine, though small, is vital to how your engine is going work. If your engine is running too hot or even too cold – this can cause serious damages to your engine’s overall health and performance. So, your thermostat is vital to your engine!

What could cause my thermostat to fail?

There are a few reasons why your thermostat is on the fritz, so we are going to give you a few indicators that the issue is with the thermostat and not another component of the car.


Just as most automotive parts, the thermostat is mass produced in a factory. Before a thermostat is released for sale, it is inspected for proper operation. The human element plays a large part in the role of inspecting the thermostats and some problems are missed. These minor defects can lead to a thermostat being defective straight from the box or failing shortly after installation.


Age is another common reason for failure. The thermostat is constantly heated and cooled, and after a while the internal components can simply wear out. This usually occurs slowly and almost unnoticed, but the temperature in which the thermostat opens begins to get higher and higher, until one day a complete overheat occurs. Unfortunately, this is just the life-cycle of mechanical components.

Leaking Coolant:

If you have coolant leaking out of your engine anywhere then this can cause your thermostat to be giving an inaccurate reading. Because your thermostat is reading that the engine is either too hot or too cold the coolant being pushed through the system causing the engine to overheat and could “bust a leak”. This isn’t the most accurate way to tell if you have a thermostat issue – there are a number of reasons why your coolant is leaking but the thermostat and the housing case is a good place to start if you see you have a leak of your coolant.

If you have any more questions or concerns about the thermostat or the housing case in your engine, give us a call at Chapman Auto Repair, we are happy to answer any questions that you may have about your thermostat.