K well ever since i owned my car i have never saw the temp gauge at anything other than the 3rd small line once warmed up and driving around…hard or even just casual…now just recently it goes wayy up…like to the 2nd last line and even between that and the last line…if i crank the heat full blast it helps and goes back down to the 4th line but i recently was driving on the 401 from kitchener to london and with the heat cranked full blast the whole way it stayed at pretty much between the 4th and 5th line…once i got off the 401 it started going up and up even with the heat still blasted…once i got to my house 10-15 mins from the 401 it was between the last 2 lines then i shut it off…what could it be?
bleed the system , and it that doesnt work - change the thermostat
how do i bleed the system?
Flush out the rad. Pour in new coolant. Looks like your thermostat is on its way out. Might as well replace it with a colder thermostat. Nismo makes one.
either that and/or your water pump might be going. monitor your coolant levels and if it’s decreasing then look into the water pump. temp gauge increase + slow coolant level drop happened to me. went away and its been fine since i replaced the pump. but if you’re changing the pump you might as well replace the thermostat too.
also, if you’ve removed your fan shroud, exhaust mani heat shield, or your rad is just toast, those could contribute to your problem too.
i had the same problem with my sr20, dropped in a new nismo thermostat no issues
Check the coolant and the oil. If the coolant looks dirty/oily or the oil looks abit milky, it could be your head gasket.