Engine running slightly colder??

[Chris_D]

I recently change the plastic housing on the front of the head wich the hoses connect to and the temperature sender sit on. It had no 'o' ring before was just filled with sealant, it was leaking water very slightly, would this affect the running temp at all? only other changes are recently changed to optimax but that couldn't affect it could it??

[KKK]

Higher octane fuel will make the engine run cooler.  Don't know why, but it's true.

KKK

[sellers]

try the thermostat mine used to run cold but now it runs fine