1998 International Truck s Oil Pressure

if it's got low oil pressure it should be making a lot of noise. But things that can cause this are bad oil filters, bearings or a bearing that has spun. BUT put a mechanical oil pressure guage that youknow is good and install that to see if you have oil pressure. Other things can be like a oil pressure valve that isn't on the pump and is stuck open due to foreign material in it.