Oil Pressure (as usual)

[blanchardkeith]

Oil pressure when first started rises to 40 stays there for the first 10 minutes of driving then slowly goes down till after 20 minutes of driving it goes below 0 and stays there. The light comes on when I first start car then goes right off. It never comes on when driving. I am going to change my oil, and filter. Does it sound like oil pump, sending unit, oil thinning when getting hot?!?
Keith
I know this has been gone over like a dead raccoon.

[pope]

Thats kind of a loaded question. How does the oil look when you change it? What oil are you using? Fiat recommends oil that is 15w-40 for all occasions. When you check under your car, is the oil pan dented on the portion closest to the ground? IF it is, it could be causing restricted pull from the oil pump which is directly on the other side of the metal on the oil pan, leading to reduced oil pressure when the oil thins out from being hot.

The fact that it goes to zero is a little puzzling, but its good to start with the known facts and trace your way forward.

[So Cal Mark]

depending on your climate, I'd use 20W/50 or 30hd oil, and mechanically test the pressure with a gauge

[bradartigue]

I had an 84 Spider that did exactly the same thing. Ended up being a bum sender. Chances are the idiot light isn't so dumb, you likely have good oil pressure. But test it mechanically or borrow a working gauge to swap yours with, or consider buying a new sender.