DanB/Steven,
If the thermostat is stuck open or leaking, the coolant will take longer in heating up correct? I suppose where I am leading towards is if the thermostat is not changed during the pump replacement and it is somewhat faulty or it is changed to a lower temp rating, this would cause the coolant to run at lower temp because we have a more effecient pump. Anyhow, I tested my suspect coolant temp situation this morning by monitoring the ECT with my OBD2 scanner from a cold start. I drove the vehicle to work and noticed the temperature took quite a while to get up to the higer temperatures. Outside temp was in the upper 60's. It liked the lower temperatures (low to mid 180's) and hardly ran into the 190's except when it slowed down or idle after a long drive. I did get the fans to turn on a couple of times after a long idle time, they switched in at about 212 deg. I had the heater blower on from the start and I notice the air got warmer as the engine coolant temp increased. After an ECT reading of 150-160 deg, I could not tell the difference in the heater air temp via my feel. During the latter part of the test, the temp gauge reached the mid point between O and R, it spent most of the time below N or just above it. The fans switched in as the gauge approached R and then headed down again.
Let me know if this is what you have experienced with your vehicle. It looks like I need to look at the thermostat a bit closer unless this is normal.
