I noticed lately, that while driving, my DMC-12 has no issues with the cooling system keeping the engine cool. However, when I'm parked or not moving (engine still running), I hear my cooling fans kick on, but my temperature gauge still rises ever so slowly while they're working. Then, when I get to moving again (not very fast, 1st or 2nd gear), the gauge drops back to the preferred temperature (about 180) within seconds. No difference when my A/C is on or off. What's going on?