Overheating

[Kiddo]

Hi, my 2 stage t-stat failed so i went and bought a new one, unforunatly they didnt have a 2 stage, so i grabbed a single and now my car goes way up on the temp gauge. Is it the songle stage or is there something else wrong ?

[Festiva Time]

Something else is wrong. Make sure you inst the t-stat the right direction. No coolant leak? Radiator fan working?

[perucho]

How do you know it was a failed t-stat? Is your water pump working? Radiator fan? Clogged radiator?

[Kiddo]

I knew it was failed by the engine not warming up, then when I replace it the engine over heats. I am sure I installed the right way. no coolant leak, and that's the thing I havent heard my fan come on. is there a way to test it ?

[Kiddo]

Ive also read that even if the radiator cap isnt holding proper pressure it can overheat the system ? so my best bets are to check the fan ? if thats working flush the radiator.

[batstiva]

Okay, humor us and double check the installation of the t-stat. The fan will not turn on until the temp sensor tells it to. (basically) If there's not coolant flow past the t-stat, the fan will not come on. You can test if the fan works at all by disconnecting the electrical connector to the fan, then it will run all the time (assuming it works). And yes, a faulty rad cap can cause overheating, because the system will not hold enough pressure to keep the coolant from boiling over. And I can verify that on an 87 Dakota.

[zoe60]

Maybe your new Thermostat is bad. Drop it in boiling water and see if it works.

[iceracerdude]

Have a look at the temp gauge sender while your at it, you've probably disturbed it where it makes it's connection.

[Kiddo]

Thanks Guys, Yeah I am going to check the thermostat this morning and I am going to check over all of those ideas. I will update.

[Kiddo]

Okay, So I checked the fan.. and it works. The coolant temperature sensor I have in the car is from a 1988 Mazda MX-6 GT Turbo. They are identical except that I am curious whether the sensor is rated higher for the Mazda, thus giving wrong reading and not actuating the fan and spiking the temperature level. I am wondering if the sensor is waiting for a higher temperature reading thus why the fan is not coming on ?

[GenevaDirt]

sounds to me like you have a flow problem....are you even getting heat out before it over heats. Not to sound stupid but make sure that you did not put the t-stat in backwards.

With the cap off and the car running do you notice flow of the coolant as the car is running?

[Kiddo]

Yeah, it had heat. turns out it was the coolant temperature sensor on by the fuel injectors.

[GenevaDirt]

glad you got it fixed.....and thanks for giving us a follow up

[Pu241]

Yeah, it had heat. turns out it was the coolant temperature sensor on by the fuel injectors.

And how did you determine that was the issue?
Because the gauge sensor is up by #4 sparkplug and the bypass hose!

[Kiddo]

I determined it by runing the codes. Yeah the gauge sensor is what I thought was the one that talks to the computer haha. until i looked further and found the one around back. I replaced it and I put a 2 stage t stat in and its perfect thanks for everyones help and imput it is greatly appreciated !