My 1999 F350s oil.pressure started acting up today. After warm-up and a short trip to the gas station, the oil pressure intermittently started dropping and going back to normal. The engine has had a slight exhaust tic so any new ticking has gone unnoticed. I stopped, checked the oil. 1/4 quart low and dark. I filled the oil and started it. Oil pressure light and gauge went back to normal. I hit the highway and the problem started again. I hoped it was the sending unit. After 3 miles at 65mph it started losing power and surging. It died in 5th gear. I tried pop-starting it in 4th as I rolled to a stop but nothing. Engine is seized and starter clicks, no crank. A smell of brake or clutch coming from the engine. Oil is full, no codes, no holes or missing rods. I'm hoping I spun a bearing or the oil pump is out and I can still salvage it. Valvetrain? What would cause it to seize up besides valve, camshaft or rod bearing?

 

Whatever damage has occurred is now done and opening up the engine may be the only choice you have to determine the cause.

Can you rotate the engine by hand ? Forget about using the starter.

 

Pinpoint F shown below:






On circuit 31, locate C1049F and C1049M shown below.


Locate C101F and C101M below:


Follow C101 to get to the pressure switch (C135).
Whatever root causes it's time to also replace your PCV valve.