XC70 -> Strange defect in the cooling circuit/sensory …

Hi together, my moose is really worried for the first time. At the Alpenrace I pushed the behavior still on the steep passes – but even there T5-Kusi wrote that it should not get so hot (with him was no movement of the Temp. indicator from the middle position fixed). At least outside temperatures above +30°C. I drive the XC70 now since 2003 and have seen the Temp. pointer still NIE above the middle of the instrument scale. Even in the AWD use in high summer with trailer operation not! The error now occurs however also at night drives (approx. +20°C and at high (>200km/h) speeds here in D. First it was noticed with Saturday morning (Switzerland, at first pass). The Temp. went quite fast and stopped at the beginning of the red area …