Vehicle Not Heating Up or Overheating: It May Be the Thermostat

If your vehicle has been running cold lately or heating up too much, you may be having a problem with your thermostat in your vehicle. Now this doesn't refer to how high the heat is you have set in your vehicle but rather the thermostat that works with your vehicle's anti-freeze/ radiator. Changing thermostats on most vehicles is a fairly easy job if you are familiar with your vehicle's engine. If not, there are books in your local Auto Zone that may help you. At some Auto Zones, they will print out a three page instruction sheet with photographs at no charge to you.

Most auto part stores carry a basic thermostat that often times are generally used in vehicles but now a days you can purchase a Fail Safe thermostat. A Fail Safe is a thermostat that has a back up of protection. If for example your vehicle starts to overheat due to the thermostat not opening for the antifreeze to keep it at the correct temperature, a second release opens quickly. This ensures the antifreeze will flow through and cool down the vehicle. Sometimes a thermostat can become stuck and restrict the flow. But the reverse can also happen. For a vehicle to warm up, the thermostat needs to stay closed until the vehicle is warmed up to correct temperature. Once the vehicle has warmed up to the proper temperature, the thermostat opens to ensure a flow of antifreeze to avoid heating problems. If you have a thermostat that is already open before you start the engine, the vehicle can't properly heat up correctly. This many times causes a vehicle to run cold even if you've been driving for more than half an hour.

When installing a thermostat, you need to make sure to bleed out the air properly before driving. If you are unable to remove the small opening due to rust or other issues, remove the cap off your antifreeze container. Run the vehicle for about 5 minutes, give or take. This will remove the air from the system. If the air isn't bleed out, you might end up overheating the car. If after installing a Fail Safe thermostat your car is still running cold, check when the engine is cold to see if the thermostat is already open. For a couple of months I didn't understand why the vehicle was always running colder than normal. While it may seem better than overheating, running an engine cold could cause damage. After checking the thermostat, I found it to be open the whole time. It was as if I was driving without a thermostat.

I went to an Auto Zone parts store to ask what was going on with this item and found out a women had not one, but three of the thermostats and froze all winter long. She also hadn't realize the Fail Safe thermostat had been opened. The product itself cost 50% more than a regular themostat. After finding out the Fail Safe was the problem for a cold running car, I was relieved it wasn't a big problem but decided to not try another one. A regular plain $6.00 themostat was put in and haven't had problems since. The idea behind Fail Safe is a good one but needs more work for it to be effective. Until this defect is corrected, I wouldn't suggest purchasing this thermostat.