The engine runs silent other than the ticking of the injectors and slight sucking of the air box so I can't belive its got much wear, i would be expecting a knocking from the bottom end if the shells are excessively worn?
From cold start the oil pressure reads right up the guage at idle.
As for the pressure sender, does it live by the crank at the front right hand side? there is a big thing sticking out that looks like a oil pressure sender and the wires have been "crimp" connected which leads me to think it might be a bit of a bodge replacement!
Plus im wondering about the accuracy of the digital dash in general
