strange heat exchange between steam turbine and the steam below it

After taking a close look to my steam turbine and it's surrounding steam, I notice something strange.

If I look at the steam below the free input of the turbine, I can observe that it's temperature change each time the turbine is spinning up. O_o

When the turbine stop working, the steam temperature is "calm" (slowly heating up by the surronding steam and the tempshift plates)

When it's active, the temperature ... "gets excited" ! (the temperature change at a high rate) O_o

This behavior breaks the system, because when the steam reach the target temperature for the turbine to work, it suddenly change and goes below, above, below, above, etc ... so the turbine have a hard time to spin up. :-/

Astraea.sav