Hi: I have a 90 model LS 400 with appx 215k on it. Over the last year or so the temp gage has slowly appeared to show the car running cooler and cooler. Now, after about 10 min. the gage will move from rest to just barely above the first hash mark, and stay there - no matter how hot outside, AC or not etc. Thinking the temp sender was bad, I just changed it and it had no effect whatsoever. While changing it I tested the gage by grounding the wire and the gage immediately pegs to the high side - which would seem to indicate the gage is working properly. The car runs fine otherwise, but I really don't like the idea of driving around not knowing true eng. temp. It can't possibly be running that cool. Anybody have any ideas?