Just picked up a 94 SC300 with 1JZ setup.. I've been searching the forum without resolve.. The previous owner was running it without a thermostat.. I put a thermostat in today, and I must've let this thing idle for 20 - 25 mins without it actually cycling temp.. it does have a nice aftermarket radiator and the clutch fan setup and its about 48 degrees out. The only way I could get any temp through the lower hose (where the aftermarket gauge probe is) was to drive it a little. But after coming back to the house, it was right back down. I want to get the dash temp gauge sorted out as well, but my main question here is: Does the 1JZ run very cold like this at idle? As in I checked the upper housing with my temp gun, and it was only getting to 165.

 

165 is excellent, usually they ran in 185 to 190 I have mine with mishimoto radiator and flex lite fans. my car take long time to temperature go up on idle on morning, but if I drive it right away I say in like 5 minutes temperature goes up quick and stays in 175~190.

 

It still seems strange that it wouldn't produce enough heat to even cycle the thermostat after a lot of idle time. Is there a special coolant bleeding procedure? Something like an air release valve?

 

Anyone care to share temp cycle or experience with such?

 

when i picked up my second setup, it came without a thermostat. so i would start with that... check to see if you have one while you at it. if there is one. replace it if you dont know how old it is... i replaced mine with a oem 2jzgte. which fully opens @82c. i'm running a stock rad with 1 electric fan constantly on. no problem at all. knock on wood .

while you are under the hood, check your plugs/replace them or regap if needed.

 

165 is great at operating temperature. I would check the coolant color and see if any is loss. I would also check the radiator cap and seal, and assure it is not bad. If it doesn't circulate still after the new thermostat, I would dig deeper, maybe the water pump not circulating and another bad thermostat. Lastly, make sure the cap is off and the heat on high on the floor when burping the radiator. Might take 15 minutes.

 

thanks guys. It just wasn't producing enough heat in the winter to open and cycle up to full temp.. The gauge in the cluster doesn't work, and the aftermarket gauge is post thermostat (lower hose).. so i wasn't seeing block/head temp, only what was in radiator. Its all good now. Thanks again. Now looking into Emanage or Map Ecu. That aem v2 is too much for me.