engine runs warmer at high speeds

[mi240sx]

When I'm cruising at 70 mph or less, temp gauge runs where my old KA24 ran, when I'm cruising at 75+, temp gauge goes up one bar on JDM gauge. I'm using my KA24 JDM radiator, with the SR20 JDM fan schoud, do I need to upgrade to bigger radiator, swap thermostat, is inercooler restricking air, I haven't voltage or resistance checked the sensor, any got an idea. Thanks it's an SR20DET

[silverarrow27]

ka24 jdm radiator???

Anyway sounds like you may have a fmic installed on your car. If so then yes most likely the fmic is restricting air to your radiator and you should get an upgraded radiator. Brand is up to you. Before you do that though...try bleeding the cooling system again. If same then you may end up upgrading the radiator. I've ran into the same issues before and upgrading the radiator always solve the issue.

[TKOcrewSR]

I would upgrade the radiator no matter what sr's ned to keep kool on my car i have a koyo which it doesnt matter which brand but i have a koyo and at first 1 12inch fan from pepboys on the right side (pass side towards the lower rad hose) and even in the dead middle of sumer it only got pretty warm one time around 225 degrees but now i have 2 12 inchers and the thing runs at normal temp but i want and suggest go with the nismo thermostat as well.

[TKOcrewSR]

ohh forgot to mention that i recomend to go with the electric fans i never had the stock fan so i dont kno how well they cool but e/f ae the way to go.

[onecrazyfoo4u]

Do you have a on/off switch on your electric fans TKOcrew? Also, how exactly do you bleed the cooling system? I've never heard of doing that, I'm assuming it's to get the air bubbles out though. Is there some bleeder valve somewhere? Sorry for the thread jack....

[TKOcrewSR]

i'm not sure about the bleeder valve but the way i would do it is let the car run from cold with the cap off add anifreeze when needed and once in a while rev it slightly to get the flow going and squeeze the top hose a little to bring bubbles out of the top of the rad. My car is a 90 chassis which came with a splice in the lower rad hose a metal tube with another temp sensor for the electronic fan which was only an auxillary for the a/c i think. The way my car was wired was with that temp sensor and wired to a unused relay in the box on the pass side i however didnt do it had it done initially with my swap but if you go to pepboys you can buy fan controllers or a 30 amp relay but you have to no wat the pin numbers mean and power in /out etc. easiest way is fan controller but you could doit cheaper with like a certain resisted value temp sensor and a relay would be cheaper but you have to no wat your looking for and how to wire it. i will search and see wat i come up with b/c im a little foggy with wat sensor to use or you could buy that factory auxillary control sensor and wire it up. its up to you but i will research and try to get more info.

[TKOcrewSR]

i'm not sure about the bleeder valve but the way i would do it is let the car run from cold with the cap off add anifreeze when needed and once in a while rev it slightly to get the flow going and squeeze the top hose a little to bring bubbles out of the top of the rad. My car is a 90 chassis which came with a splice in the lower rad hose a metal tube with another temp sensor for the electronic fan which was only an auxillary for the a/c i think. The way my car was wired was with that temp sensor and wired to a unused relay in the box on the pass side i however didnt do it had it done initially with my swap but if you go to pepboys you can buy fan controllers or a 30 amp relay but you have to no wat the pin numbers mean and power in /out etc. easiest way is fan controller but you could doit cheaper with like a certain resisted value temp sensor and a relay would be cheaper but you have to no wat your looking for and how to wire it. i will search and see wat i come up with b/c im a little foggy with wat sensor to use or you could buy that factory auxillary control sensor and wire it up. its up to you but i will research and try to get more info.

also dont let the car get to warm when bleeding it wen it warms up and you see a constant coolant flow put the cap on and fill the resevoir.

[silverarrow27]

Jack up the front of your car on jack stands or drive the car up on ramps which I recommend. Air moves up!There's a 10mm bolt on the upper metal coolant passageway on the head above the powersteering pump. Unscrew the 10mm bolt and pour in coolant/water until it's spurting out in a nice stream. Screw the 10mm bolt back in and leave the radiator uncapped. Turn the heater on to full blast and turn on the engine. Do that for a good 5 minutes or so and should be good to go.