as title reads

To the best of my knowledge all the OEM thermostats on the WRX and STi fail closed. I know the early WRX had the standard design which fails closed.

Had that happen on my 88 subaru which is why I went with the Crucial Racing coolsafe thermostat when they came out.

Larry

Funny to come across this as I went to the auto parts store and asked them this very question today.
I was replacing my water pump so I took the thermostat with me. I was told by them nearly all aftermarket thermostats (performance ones or oem) fail open. He said this is due to the major damage that can be caused by failing closed.
Thats not to say that the above post is wrong, it may be that the oem ones fail shut. From everything I have heard the crucial ones are very good just very expensive.

anyone know for sure about modern, stock tstats?

anyone know for sure about modern, stock tstats?

As I stated above "I know the early WRX had the standard design which fails closed."

What is supposed to be "common" in Australia has very little to do with what you can buy here in the states. The standard base model thermostate is and has been for over 60 years a fail closed design. The fail open designs have only been available as extra cost options at the parts store for a relatively short time. They are pretty easy to find, just look for the replacement thermostats that cost 2 - 3x what the standard "fail closed" thermostat costs.


Larry

I know people really like the crucial racing Tstats...seemed to be built very well. Being that I am still on the stock turbo and don't have cooling issues, I'd like to get a high quality one that is fail open, but is maybe about 5-7 degrees colder opening than the 12 degress of the crucial. know of any available?

....but is maybe about 5-7 degrees colder opening than the 12 degress of the crucial.

Just out of curiosity, why would you want a cooler than Crucial tstat?

MT :devil:

Just out of curiosity, why would you want a cooler than Crucial tstat?

MT :devil:

:p , I meant cooler than stock, more hot than the crucial. Say, opening around 165-167. Because I am still on the stock turbo, I think I may run too cool with a crucial...but the idea of using a fail-closed Tstat (when fail open is readily available) is moronic to me.

:p , I meant cooler than stock, more hot than the crucial. Say, opening around 165-167. Because I am still on the stock turbo, I think I may run too cool with a crucial...but the idea of using a fail-closed Tstat (when fail open is readily available) is moronic to me.

Ah! I see. I thought that you were saying cooler than Crucial :eek:

I recently removed my Crucial because I was getting a tstat malfunction cel. I took it out, tested it and everything was fine. :confused:

I've since thrown the stocker back in and no more cel.

MT :devil:

hmm...i guess there is a sensor that monitors water flow and found that yours was flowing when it was not "supposed" to.

Stock tstat fails closed.