The oil from the oil pump is led to the channel that goes directly to the cooler and the
thermostatic valves. The oil flows outside the tubes and moves in the upward direction.
After the thermostatic element, the oil flows to the channel that leads to filtration and
delivery. Low-temperature cooling water flows inside the tubes. When the oil temperature
rises, the valve opens and lubricating oil flows through the cooler. As the cooler becomes
dirtier, the temperature rises a few degrees as the valve needs a certain temperature rise to
increase the oil flow through the cooler.
It is possible that we have a valve not operating to its full potential but it seems to be operating correctly.