hello, on my 87 245wagon i recently replaced the alternator drive belts and thermostat. I did the thermostat because i thought the old one might be having some issues. Previously the water temp gauge would basically go up an eighth of the way up. and every once in a while up to a quarter of the way up the gauge.

then after the replacement was put in, now it holds steady at a quarter and will go to the 9 o'clock position for while, and then go back down to a quarter. this is based on an 80 mile trip that i've been doing twice a day for the last 2 days. so i know the engine so be up to normal operating temperature. Is this something to be concerned about? Should i replace the thermostat again?