Every Time I Put My Thermostat Back Into My Car, It Seems To Over Heat And Leak Coolant. Why

Posted in Cooling Perfomance

I drove my car 6 hours straight without the thermostat in, the temperature was fine and it didn’t leak. I put it back in today, drove 10 minutes and it almost over heated and I saw coolant leaking.

There are 8 Answers for "Every Time I Put My Thermostat Back Into My Car, It Seems To Over Heat And Leak Coolant. Why"

    1. livn4themin says:

      your thermostat is stuck/broken. Get a new one.
      Check out your water pump as well.

    2. wazzup says:

      is the leak the overflow pipe?
      is it in backwards?

    3. sweetielovebear1 says:

      you need a new thermostat, its stuck shut, you can get a new at any auto store,

    4. Ford Maniac says:

      well more than one thing can be happening but in my experience the thermostat is probably bad and its sticking causing your gauge to read hot and your motor to react with this and overheating. you can try cleaning the thermostat or better just replacing it.

    5. psysciguy says:

      Livin4the… and wazzup have it. Bad part or in backwards are the most likely causes.

      Leak could also be:
      * A bad gasket – in some cars it’s part of the thermostat.
      * Improperly torqued parts – especially in AL engines
      * use of wrong type of gasket sealer
      * either using a sealer when not needed or NOT using a sealer when it IS required.
      * swapping long and short bolts – some engines have different length bolts. If they are interchanged the long one bottoms out and doesn’t tighten the parts together
      * warped parts – unlikely but possible
      * sealing surface damaged – did you pry it off with a screwdriver?
      * wrong thermostat – more common than the parts guys admit

    6. Jack V says:

      well the t-stat could be bad and stuck and should be replaced, however when the t-stat is in it should cycle open and shut if there is a weak spot in the system it will obviously leak there. when it is in and is cycling it going to increase pressure in the system and therefor leak at the weak spot, if it just at the overflow then it is most likely the t-stat it’s self. they are very cheap but somtimes hard to get to. good luck!

    7. patho says:

      test the thermostat by heating it up in a pot of water on the stove to see if it opens fully. if good then u probably installed it upside down in the engine.

    8. baldie says:

      are you getting it in backwards?, the spring goes in the block.