If you have noticed that your car has started to overheat after only a few minutes of driving, you may be wondering if there could be an issue with the radiator or if there is a coolant leak somewhere in the system. However, if you notice that your coolant level is normal and do not find any leaks, the problem could be with the thermostat. If you suspect that the thermostat may be failing and needs replacing, look for the following signs while you are driving.

1.  Sudden Temperature Changes in the Air Coming Out of the Interior Vents

One sign that your car's thermostat is going bad will be noticeable while you are inside of the vehicle. When you are running the heater, you may notice that the air coming out of the interior vents will suddenly become cold for a few minutes before it heats up again. If you are running the air conditioner, the air may heat up then rapidly become cold once again. You may even see steam coming out of the vents.

As part of its job, the thermostat regulates the flow of coolant through the engine, which will affect the air temperature coming from the heater or A/C unit. If the valve inside of the part is stuck open, the temperature will drop. If the valve stays shut, the engine will heat up, causing an increase in the air temperature.

2.  Rapid Changes in Readings on the Dashboard Temperature Gauge

Along with drastic changes to your car interior's air temperature, another sign for which you should be on the lookout is rapidly changing readings on the dashboard temperature gauge. When a thermostat is going bad, it is a misconception that the gauge will show abnormally high readings. Since the temperature will depend on whether the valve is stuck open or closed, you may see the gauge read dangerously high one minute followed by a very cool reading. Either way, the rapid fluctuations in temperature can be detrimental to your car's engine and needs to be seen to by a professional as soon as possible.

If your car is showing signs of a bad thermostat, the faulty part should be replaced before it fails completely and leaves you stranded because of an overheated engine. Take your vehicle to an auto repair service to have a technician see if the thermostat is causing the issues with your car so that they can change it out for a new one.