Alfa 159, oil temp running hot but not water temp?

[JakeChoules]

Recently my Alfa 159 1.8 (2008) has grown a habit of running its oil hot. Once driving the oil temp will climb and climb the harder the car is pushed, it will eventually stay at a constant temp once sat at a constant speed (e.g. sat at 70 it will sit at 130'C)(normal running temp is 110'C). I haven't dared push the car so much as to push it past 135. All the while the water temp will stay bang on normal running temp.
The only other relevant information i have is that leading up to when this started the radiator had a small leak to so I had used stop leak to patch it.

anyone got any ideas as to what could be causing this and/or how it could be remedied?

[Unbusy]

Where is the needle with the ignition on, cold engine?
If it is anything but ambient then something is wrong with it, rather than the engine.

[JakeChoules]

The temp needle stays at 0 when the ignition is on and engines cold