no flow on oil cooler

[carrizog60]

hello

my oil cooler doesnt warm and i am thinking the problem might be the sandwich playe assembly.
i dont know if i have a thermostat but i remove the thing inside(thermostat or one way valve?) but that didnt help at all.
might be a thermostat as it shows a number on top...cant remember what is...
does anyone have a pic of the assembly so i can see if its a thermostat?

what can i do to test the oil cooler system and find a solution?

thanks