What are the chances of it being just a head gasket failure?

[Detroit80]

1990 F350, 7.3, 5 speed, Banks Sidewinder turbo. No clue of real mileage, last title change said 275K, I've probably put 20-30K miles on it since buying it, but odo currently reads 33K... So I don't really know, lol.

Truck was off the road for about a year, only occasionally fired up to play musical vehicles on the property to get to other vehicles/trailers that were behind the truck.

I've put maybe another 1K or less on it since putting it back on the road, seems to be running fine until today.

On the way to work, cruising at 65mph, I start noticing a faint burning smell, kinda like a trash fire in the distance. Truck still running good, gauges all look normal..

About a mile or two later, I get off the freeway, truck starts running rough, and it's BILLOWING white smoke out the back... Seriously huge cloud. I pull over and shut it down, pop the hood, and everything is absolutely soaked in coolant. I tried firing it up again, restarts immediately, feels like it's missing on a couple cylinders, still blowing a huge amount of white smoke, and notice it's also dropping raw oil out of the exhaust.

I let it sit for about 30 minutes, and then limped it into my work parking lot a mile away so I wasn't sitting on the side of the road. Stopped smoking, but I could just be out of coolant, lol. Definitely running rough, but not as bad as before.

No evidence of oil in the coolant overflow bottle, or coolant in the oil based on dipstick condition, and oil isn't low.

I've blown plenty of head gaskets in cars over the years, but I've never had one that sends raw oil out of the exhaust when it happens. But I've also never really got into diesels other then this truck either.

Still with the truck at work, so haven't been able to do any kind of real diagnostics... Does this sound like a simple head gasket or gaskets gone (I'd replace them both anyways), or something much more terminal within the motor to the point I should be thinking rebuild trying or looking for another motor and/or truck?

 

[riphip]

Hopefully head gasket but with those miles, possibly cavitation.

 

[IDIBRONCO]

Here's a little bit of good news for you. What's dripping out of the exhaust most likely is coolant, not oil. The coolant's covered with soot from your exhaust so it looks black.
I'd be leaning toward head gasket over cavitation for one reason. Cavitation won't make your engine feel like it's missing while running.

 

[Macrobb]

Yup, sounds like a head gasket to me. Just make sure you tear into it soon. Or, if you don't plan to, drain all the coolant, and fire the engine up for ~30s or so(not much longer), to get all the coolant out of the cylinders. Don't want any rust or coolant in the oil.

 

[Detroit80]

Here's a little bit of good news for you. What's dripping out of the exhaust most likely is coolant, not oil. The coolant's covered with soot from your exhaust so it looks black.
I'd be leaning toward head gasket over cavitation for one reason. Cavitation won't make your engine feel like it's missing while running.

Ahhh, makes sense on the oil. It was jet black exactly like the oil on the dipstick, and felt oily as well. But I was thinking it was odd that given the size of the puddle on the ground, and the size of the clouds behind me, that it sure seemed like the oil should be low as well. Granted, I didn't do much of a complete inspection at that point, as I more attempting to beat down the urge to say "F it!", take the license plate and VIN tag, then walk away. Eventually realizing that I had about 5 grand worth of tools, equipment, and radios in there as well made that urge subside, lol.

I was concerned about the cavitation from the standpoint of it being what would have initially kicked off all of this chain reaction.

I'm thinking water pump failure may have something to do it with it too now, or maybe even just lower hose failure/leak, as I noticed after I put a couple gallons of water in the radiator and drove it back out of the work lot for the tow truck to pick it up (I park inside a very secure area, and getting a tow truck inside would be a major PITA dealing with security), it was pouring water out under the radiator area. Had only been running for a 3 or 4 minutes at that point. Closer inspection revealed that it appears as coolant was running down the outside of the lower radiator hose.

At this point, this truck was my last running/driving vehicle...this will be number 5 vehicle failure this year (seriously..what curse did I pick up?!?!?), and I'm thinking swapping a trans from my Chevy truck (with failed injection pump) to my Blazer is going to be the quickest way back to a driveable vehicle, followed by tearing into the Ford. So it may be a few days until I can get to it.