Thermostat Repeatedly failing under normal Operating conditions

[Hoverjetb]

Hello Folks,

I would first like to say that If there is another thread that has already answered this, please point me in the right direction!

I have a 2006 Legacy GT with ~170,000 miles on the chassis and about 6000 miles on a completely rebuilt motor. It has forged pistons and rods, brand new long block with stage 2 cams, and a VF52 turbo on a 0% waste gate duty tune for break in.

I finished my break in at 5000 miles and I was about to begin tuning when my OEM thermostat died. I know, I know... should have changed it when I was rebuilding but I missed that. I changed it with an Advanced Auto thermostat and that died after 60 miles. It killed my radiator because I thought i could push the high temps for longer then I actually could so I ended up having to replace the radiator and the thermostat. I now have a Napa Thermostat and radiator with roughly 1000 Miles on them together and that Thermostat just died.

I am looking for suggestions on what I can do for troubleshooting because something is wrong and it cant be the thermostat. I would like to fix it before I run through any more thermostats.

Thanks for your input!

[silverton]

Your OE thermostat lasted 170k miles, why not try one of those?

[Infosecdad]

OEM thermostats only. Aftermarket never got that part right on Subarus.