WR Ur quattro, oil filter housing.

[Colin Aitchison]

Hi Guys on the scrounge for information, my WR Ur quattro 1984 oil temp goes up very quickly and take for ever to come back down, when I was parking the car the other night, I went below the car to feel how hot the oil cooler was, it was quite cold, from memory it is normally very hot.
I may be corrected on this, but, my thought are that the oil filter housing has a bimetal oil stat and what looks like a piston and spring in it on the parts menu, this is accessible from the cover on the end plate of the housing, has anyone had one of these in bits or has any other useful information on repairs, I do have a couple of spare housing but not wanting to bin a part if it might be something very simple to fix like a stuck piston.
Thanks in advance.