Truck Repair: truck shuts down, coolant level, cam bearings

Question
I have a 1994 freightliner that has an N -14 370.  I just bought this a few months ago.  The problem that I am having is that the shut down light comes on and the truck shuts down.  Oil temp --- 200 deg.  Water temp ---- 180-200 deg.  Oil pressure running with a load at 15-1600 rpm 20 - 25 psi.  I've been driving the truck around but just without a load.  Load brought out the problem I am guessing.  Changed oil and filters.  Checked piston oilers.  Engine has 981,000 miles.  Previous owner replaced connecting rods and installed sleeves.  He did not replace the mains or cam bearings.  I have just installed a new oil pump but I don't think that was the total problem.  I think there is something wrong somewhere else also.  Could misadjusted valves cause oil pressure to drop like that once it reaches 180-200 degrees?  I am going to try the mainbearings next.

Answer
Need to find which sensor is at fault,oil water temp,coolant level,or air intake temp.Turn key to ON pos,turn cruise to ON..wait for the check cycle to complete then hit the resume or set switch & count the flashes.There will be a 1/2 sec pause between digits & a 1 1/2 sec longer pause between faults with the RED Stop engine light.Let me know which fault it is & Ill tell you which sensor it is.