sr20det water temp

[Kei_ayanami]

sr20det water temp

Hi guys the water temp on my s15 sr20det its idling around 87-95c.
Driving around 60-70kmpm it idles around 85-89c and if im doing highway speeds at 90kmph or more it rises and sits around 95-100c.
I cannot run the air con at all if i do it will hit 110c+ and the stock water temp on the dash will also go into over heating.
If i turn the heater on then the water temp goes back down to around 80-85c if i turn the heater off the it rises back up again.
I have changed out my thermostat for a brand new one and i have flushed out my radiator there isn't any leaks as well the coolant is topped up so i have no idea why my water temp is running so high. 
Everything is stock.

The only problems i can think of is my stock oil temp sensor the part that goes into the engine is broken so the electrical it isn't connected Not sure if this will have anything to do with my water temp running so high.
I'm running a after market water temp and oil temp gauge. 

any help or thoughts on the problem would be greatly appreciated.   I don't want to go out a buy a brand new $600 radiator if it isn't the problem.......

Edited December 15, 2016 by Kei_ayanami

[admS15]

Your radiator is probably partially blocked. You could get a radiator place to clean it properly or just replace it with 1 of the million cheap alloy ebay radiators for under $200 delivered. I would go with the second option. I have used a few of those radiators and never had an issue, even when pushing hard on race tracks.

[Duncan]

Without pressure testing the radiator (a mechanic could do it, takes about 10min) it's hard to be sure there are no leaks.  Assuming no leaks, I agree it sounds like a radiator issue and replacing it should be well less than 600.  Justjap have them under $250 and it's reasonably easy DIY

[89CAL]

Was the system bled properly?

The fact that your issue occurs at higher speed suggests a flow or heat transfer issue so radiator or water pump i would think. Sounds like your radiator though. Pull it out of the car and have a good look at it. Flush it again. Fill it up while covering the bottom outlet and then check how the water flows out. Check the fins and check for any obstructions in airflow