The 1600 engine in the 1978 wagon has low oil pressure when it warms up. The light started to flicker at a very low idle. The book said it will do that if the oil pressure gets down to about 2.8 psi. I relaced the sender with a mechanical gauge and when cold I have around 50 psi oil pressure! When it gets warm it drops to about 5 psi. I'm using 20-50 castrol oil. Any ideas on how to raise the pressure? Or should I not worry about it? The motor has NO ticking or off sounds. As a matter of fact, this is the quietest 1600 motor I have ever had. What do you all think? Thanks...Dennis...

5psi is marginal, but as long as it doesn't drop below that it should be ok. What does it sit at when cruising?

With the engine at normal operating temp, it is running at a constant 25 psi. That was going up and down hills, on a flat and cruzing at 50mph. Even at 25mph in 3rd gear it was still 23-25 psi. Lugging it a bit to see how much drop I would get. Do you think it would increase if I put a new oil pump in it? Or just the usual bearing problem on a slightly worn engine? I've got good power and no smoke, doesn't use ANY oil. Maybe I'll switch to racing 40# and see what happens.

That is quite low, i would try changing the oil pump. Your bearings would have to be quite bad to give a pressure like that.