Oil pressure drop and wont start.
 

My 97 cummins ideling will drop to 0 oil pressure u give it over 1500 rpms oil pressure kicks up. when u drive it at a steady speed itll drop back down. temperature is fine. oil level is full and the last two weeks its gotten harder and harder to start. barely started before all this happened. cleaned all terminals starter and batteries. i did notice tho all my coolant is gone now and i checked it 2 weeks it ago and it was full. and now since it has sat over night it will not start at all and has 14 volts. my guess is my intake or head gasket was breaking and its just been taking water on the top of pistons and its been harder and harder to start bc it has all the pressure from the water and now it wont start. sooo please let me kno what u think

Won't start or won't turn over? Missing coolant should = high oil level or its sitting on the piston which could be several things...Head gasket blown, cracked head or cylinder wall... Oil pressure could be a bad sensor (had to replace a few that got old so i went to a mechanical gauge)

sounds like a blown headgasket and a bad sending unit