So after a track day I swapped back my MY01 ECU and drove home.

The coolant temperature reported via ODB2 never went past 158 degrees.

I could turn the heat on and it felt blow dryer hot and the coolant temp dropped to 152 degrees.

My car has a 3 core aluminum radiator but normally it will reach 190 degrees no problem.

Is my t-stat stuck open? Any method to test this?

Any other ideas?

 

Are you getting 3 bars on the dash temp gauge ? . I had a thermostat stuck open on my s2000 and the car would not get much above 2 bars on the temp gauage, occassionally it would hit 3 bars but then it would drop back down to 2 bars. The larger aftermarket rad shouldn't affect things much in normal daily driving if the thermostat is working properly, unless you have a lower temp thermostat and rad switch.

 

I only got 1 bar when I drove home.

The t-stat and rad switch are OEM.

I have the modifry temp gauge fix since I run an AEM 1052 on the track however normally I see 3 bars everywhere.

 

I think the only possibility would be the thermostat. I don't know how you could test it, I guess if the thermostat is stuck open all of the rad hoses and radiator temp would be the same temp all the time, not much of a test.

In my instance I installed a Mishimoto radaitor and a large chunk of aluminum weld material washed out of the rad and lodged itself into the thermostat that prevented it from closing.

 

+1 Mine used to drop down to one bar on the freeway. Replaced thermostat and went back to normal. Back in the day we used to throw the t-stat in boiling water to check if it was opening. No way to check it without getting it out of there I think.

 

ok thanks guys i guess ill order a new one from handa