Is my wagon toast? Oil pressure bouncing madly

[aaa]

83 TD. So after a long trip, it seems the fan clutch has given out. Anytime I stop, the temperature goes up.

After one hot episode of bumper-to-bumper traffic (managed by the heater, haha), the oil pressure decides to go crazy. I am talking about the needle bouncing madly enough to make a buzzing noise. It settles down to a twitch when the car is cool. Anyhow, the pressure has twitched (a little) like this one or two times before (months ago?), I put it out of my mind since it wasn't continuous. Well now it is continuous.

So any advice on what to do? I was thinking about sticking some 15w50 in it or something. Oh, and a reminder on how to diagnose fan clutches would be nice, might swing by a jy and grab one.