I noticed the stock temperature gauge was dropping a fair bit from the 'just below center' position its supposed to sit at when i was driving at speed, thought aha! - a classic sign of thermostat not staying shut, so got a new one ordered from TCB.

It's a NIPPARTS J1532015 according to the box and stamped into the thermostat it states 76 degC. Have TCB sent me the wrong part? This sounds very low - Maybe my car already has one of these fitted which is causing the temperature drop at speed but i've not checked yet.
I expected a standard thermostat to open at ~85 degC+. Anyone know for sure?

I believe that the stock thermostat controls temperature at 82degC

A trd/performance thermostat will probably be nearer 72.

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Toyota Celica GT4 ST205
Toyota Celica GT4 ST185

As above , the trd stat is 71 degrees the 76 degree stat you have been supplied is a much cheaper option ti the trd variation that tcb sell

Martin

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In the current cold weather my engine is running at around 60deg C on a stock ST205 so based on this there may be nothing wrong with your thermostat. Measured from my Defi coolant temp sensor located in the top hose (hot coolant exit from the head) which feeds the standard radiator.

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GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
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Yes, the stock one is 82°C and the TRD is 71°C .

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The thermostat that has been supplied will be fine, infact, beneficial - especially during the summer months.

To check your old thermostat.
Put it in a saucepan of water and then heat the water up on the stove.
If it is working correctly, when the water gets hot, you will see it open.

HTH

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