"Jumps" as in a springy action or as in rises quickly to center? Mine always has done the latter, even in cold weather. It's a little slower under, say, 10 degrees F, but at that point I'm usually plugging it in, so it really races up to temp. It definitely let me know when it started to overheat after the headgasket went, too.

~Adam


96 T100: D44, lockers and stuff