So I changed everything on the cooling system except the pump. Dual belts, thermostat, and even the radiator. I had a clogged koyo and i was seeing 5-10 deg increase in heat. So now it stays under 180' like before, no more 190-192, so thats good. But it's still a few deg hotter than before. And odd, it climbs and drops 5-7 deg as i drive, stop, wot, whatever. It will climb and drop so fast you can watch the gauge just move up and down.
The pump isnt leaking and i removed it and checked the fins, all good. Could there be something else wrong with it? It;s the only thing I havn't changed. I changed the belts but could it be slipping internally, if thats at all possible? Or not moving the water well enough?

The new koyo i got also has the koyo imprint on it. My old one didn't. (1 year old) Aslo the side looked like it had the brackets mounted to them before. You can see the lines down the side. Anyone know anything about these koyo's and are the ones with the stamp different?

 

Why are you worried about little temp fluctuations? It's not like the thermostat snaps open and closed.

Actually it's a good sign- it means the pump is flowing well...

 

A Koyo clogged in 1 year ? Sound to me like everything is fine. Those temps aren't bad at all.

 

Temps wouldnt be bad if they had always been like that. And its actually always fluctuating, never stops, up and down. It did go above 180' tonight for a second at wot in 3rd to redline, then dropped right away after I let off. The problem is that i track this car. I can't go as fast on the street as I do on the track, so I have no way of knowing how hot it will get from all the track abuse. Im betting though that if it goes above 180 in one gear on the freeway at night, it will definitely get hotter on a hot track, hot day, with that type of driving. Thanks guys! Any other idea's?

Im changing the pump tomorrow morning!