Hello All,
Looking for a little help on diagnosing a problem with my truck. I have a 2008 F250 Lariat 4X4 Diesel, Crew Cab, Long Bed. The truck has just over 162K miles, and had the turbo's replaced at 148K. I was towing a 15K pound fifth wheel, and about 15 miles after a fuel stop, the truck began running EXTREMELY rough. I pulled to the side of the road, and shut off the truck. It would not restart, so was towed to the nearest dealer (100 miles to Amarillo, TX). The dealer told me that the crank shaft in the motor was broken. I continued on my trip with a new truck, but picked my old one up 6 weeks later. I emptied the fuel tank, fuel lines (blown dry with air), all fuel filters and changed the oil. I added some new diesel to the tank and purged the air from the fuel system. The truck started then, but was running a bit rough. the longer I let it idle, the smoother it began to run. After about an hour of idling with occasional 200-300 rpm revs, the engine stalled and would not re-start. I had to let it set for a couple months due to work, and I found the rats or squirrels got in and ate through some of my wiring. I repaired all of the damage to the wiring and installed new batteries. The engine will crank, but very slowly, and will not start. Does anyone have any ideas for me to look at? I'm thinking that maybe the main bearing spun and are causing excessive drag on the motor, but I am just not sure. Any help will be appreciated.

 

If the question is "are the bearings spun" then the answer involves pulling the motor..... the 6.4 is pretty well known for eating bearings due to fuel dilution of the oil. If you want to keep working it and not have it turn into a full blown rebuild project just short block it and move on.