i have similar problem...it goes over just a little bit, you can't even notice it sometimes...and than sometimes stays under the half, again, just a little bit. I have 175K km on it, and the pump was changed at 113K km. T-stat was changed, i can't think of anything else. I will have it flushed soon, but Stage36 (i think that's his nick) thinks it might be my coolant temp sensor (we determined this on the topic i posted about this problem) I haven't changed the temp sensor, but am thinkin' about it. We'll see what happens!