Cracked block?
 

I offered to work on a friends truck with the assistance of my brother in law(industrial diesel mechanic). Owner felt he had a blown head gasket(oil in coolant, blew it all over the engine bay, oil pressure fell quickly but he shut it down before it bottomed out).

We had the head gone over(new valves, seats, springs, decked etc) was over $500 in work and the guy has a great reputation. Bought cummins marine gasket, and Mighty Diesel head bolts, turbo turned out to be shot and may have even contributed to the problems at hand. It was also professionally rebuilt to the tune of $450.

We flushed the heck out of everything, hoses, heater core, had radiator dipped, and it turned out to be leaking and unrepairable(basically) so it got a new radiator as well that has yet to be dropped in as we wanted to run straight water in it for a while to flush it while running.

We had the oil cooler tested at the radiator ship, I watched as they plugged the lines and applied air pressure to it, held it under water and waited for bubbles, they never came. Reinstalled with new oem cummins gaskets.

We haven't even had the truck fire up yet(came close, still air in the lines) but the oil has turned very milky without even running! I'm worried as hell there has to be a crack in a passage some place or something, to leak bad enough to show up before the motor even runs seems kind of crazy.

Head should be fine.
Gasket should be fine.
Cooler was tested and found to be fine.

Followed torque specs and methods, wrench is accurate as well, used degree wheel when that was needed.....

Looking for thoughts and opinions on how to proceed on this old girl. My buddy has alot of money in this old girl now, she has 230k miles on her also.


Thanks guys.

It's possible. Mines got a crack like the 24v's crack on the outside of the block that is supposed to be fixed Tuesday.

this dont sound good. hope it is just remains still left in the block.

I'd just think it's left over in the block.. Usually on a cracked block the oil will seep in while running (from the oil pressure.. vise versa). I'd flush it real good and go from there..

I didn't even have the radiator cap on, shouldn't be hardly any pressure at all on the coolant system to cause it to leak into the oil. I flushed all the coolant passages out well, and I'm not seeing any oil in the water thus far, just water in the oil. I'm going to drain the oil out, and let it sit and check the pan in a few days after just sitting to see if there is any volume of water that shows up.....

At that point I figure if I do have water, I'll pull the oil pan and see if there is anything to see.

what about the coolant galleys in the block where the coolant flows through to cool down the cylinders??

I pulled the engine oil cooler back out, I thought I could actually hear water running over there with the filter off, it'll pour water out of the oil filter location.

After pulling it off, I ran a straight edge down it...the bastard is warped and pulled! Not sure precisely what caused this, but I'm going to get a new set of gaskets and a new oil cooler, have the external filter housing plate milled to make sure it's perfect and try again.

I wish I could find the damn engine serial number, the tag is long gone.

Wish me luck, and opinions and thoughts are still most welcome.:argh:

im in a similar boat with a 98. any luck? comperssion check? i have full comperission. but coolant pressure is bleading off. water in oil. not much in coolant. new head- gasket studs. professionally done. milled head. everything. afraid have cracked coolant passage. let me know what u found. please.

Turns out the oil cooler was actually warped and not sealing up as it should allowing massive oil/water sharing. Bought a new one and gasket and it cured the problem. Definately strange as hell in my mind, especially to happen for no apparent reason. Tons of water oil as the bigger issue. Considering the cost of these blocks, it's worth a shot I'd say.

did the oil cooler. no help. usually u can hear them bleeding off, when u pressurise the cooling system. i got nothing. no external leaks.