redone GTR not heating up?

[G.T.R]

Okay well I rebuilt the top end of my car, it has a copper rad, new hoses, fresh coolant and a nismo thermostat. But for some reason the most the gauge goes up to is the C mark or a bit higher. But the engine feels warm. and at operating temp, and the oil temp rises aswell. Wanted to know if this is a problem of a dead sensor or something else. This has me worried because I dont want to drive it hard and have my work blow up cause I cant read the water temp I was gonna run a water temp gauge but want that to be a last resort since I am trying to keep the factory look. I know the location of two water temp sensors, one on the runners and one in the rad are there any more?

Thanks
Steve

[Brendan]

Is it a low temp thermostat?

[natetheguy]

Is it a low temp thermostat?

yes the nismo thermostat is 15 degress lower than oem, but that shouldn't matter. I have a nismo thermostat and my car reaches normal operating temperature just as fast as any other gtr.

[archaeic_bloke]

the oem water temp sensor takes its reading from the radiator part... which only happens AFTER the thermostat opens... before the thermostat opens there is no reading, or very little and the result is exactly what you describe...

i would say your nismo thermostat is NOT opening properly. take it out and check it.

to check the thrmostat.. put a pot of water on the stove... turn on stove, drop in thermostat... when the water boils the thermostat should be CLEARLY open.

its a cheap quick test you can do yourself... do it.

[malibusst]

Temp is actually seen by a sensor on the top rad hose, not the one in the rad, that's an auxiliary fan switch