in contrast to the other thread: when idling, the car warms up fine and the temp gauge gets to 12 o'clock and all is well; heat flows from the vents.
when underway, the temp gauge drops to 10 o'clockish and i don't get any heat (or really anything at all) from the vents; returning to idle and waiting sees the temp gauge rise back to 12 o'clock and heat resumes from the vents.
doesn't seem like a t-stat or water pump issue, because the car does indeed produce heat and get up to temp when idling.
coolant temp sensor?
thanks all!
peter