M932 with water in the oil :(

[KSMTRUCK]

Got my 932 out this afternoon to clean it up for a local student who wanted to take it to Prom tomorrow evening only to find out that there is water in the oil! NH 250 Cummins

Where would you first start looking ? Oil cooler?? Head gasket?? Liner??

As always any and all help greatly appeciated......

 

[m16ty]

Oil cooler would be the cheapest/easiest fix so I'd start there first. It's not uncommon for a 250 to eat up the sleeves either if the coolant isn't kept in good shape.

If the oil cooler checks out ok I'd pull the pan, pressurize the cooling system and see where the coolant is coming from.

 

[wreckerman893]

My logger buddy and old school Cummins guy says that if a Cummins sits a long time and is restarted you can sometimes get a leak through a cylinder liner.

 

[KSMTRUCK]

Thanks Gents...........I think I'll drop the pan and pressure up the cooling system to see if I can spy a leak. on a liner. Could a head gasket leak around and down a by a push rod??

 

[WillWagner]

Drop the pan and pressurize the cooling system. If it's a cooler, it will leak coolant between the mains an crank, If it's a liner, it'll come from between the piston and liner. if the freeze plugs in the head are leaking, you'll see it dripping/running from the push tube cavity. Is the coolant antifreeze or water? Taste the stuff in the BB tube. If it's sweet, it's antifreeze, if not, water.

 

[KSMTRUCK]

Roger that WW!! That will help alot. This is a very clean low milage truck from Camp Shelby thats in great shape.....shame this has happened, and to answer your question it's anti-freeze in the oil. Drained all coolant out today. Flushed motor with kerosene 3 times today.

Pulled the emergency fuel shut off during the secocond flush and rotated the engine over then drained and flushed again.

Jeff Oakes

 

[droprat]

Pleae let me know what you find.

Friend of mine picked up my 1983 Am Gen M-931 truck tractor from Ft. Bliss, TX couple of weeks ago. When I drained the oil, about 2-3 gallons of coolant also came out.

The truck was running fine all the way home with the exception of some smoke/vapor and oil coming out of the crankcase breather tube.

Info shows that the truck was rebuilt at Red River in 2006. Mileage was 300 miles and 10 hours on hour meter. I am sure it sat for several years.

I have heard to run it hard in order to break it in? Oil cooler? Cylinder liners? Head gasket? I have not done anything but drain the oil and coolant.

Thanks Rich

 

[KSMTRUCK]

I have pulled the oil cooler and it looks fine. Waiting on new gaskets and o-rings to put it back on then I'll drop the pan and dig in deeper. All but 2 gallons of my cooling system was in the oil pan so I'm guessing a liner ? This is on a 5 K mile/ 1000 hr truck per gauges...whatever thats worth??? I think a sweet little 290 turbo would be a nice fit!

 

[droprat]

Thanks

Thinking a liner may be my problem also. I have barely started to dig into the oil cooler.

Keep us posted.

 

[railroadmike]

I just cored a M923 from an auction, after jump starting it ran great everything worked. Later noticed steam and liquid coming from the vent tube, after finding low coolant level found the oil was compromised. I don't know how much made it into the oil but immediately dropped oil and coolant at a truck stop, added straight water and pepper, fresh oil and drove 20 miles home. I was unable to drain filter and water made it back into the oil. Low mile Low hour tuck, If its a liner Im guessing the engine has to come out? Ive rebuilt B series with good results, worked with older Detroit engines, not familiar with NH250. is there a way to get them to seal up? It does not appear that water has gotten into the combustion chamber.

 

[droprat]

We ended up parting the entire truck out. It was our first MV. My son and I learned quite a bit!

Truck was an M931A1, rebuild out of Red River. Low hours and miles! Truck was immaculate! Anyways pressure tested cooling system and it turned out to be several bad liner seals. This caused a host of other problems; ruined bearings etc!

We decided not to dump anymore $ into it, so parting it out worked out good.

The NHC 250 can be rebuilt pretty easy from what I have gathered on this site! As long as u know what ur doing and have parts and tools available!

Good luck and we are here to help! Don't let that milkshake in ur oil pan get you down!!!

Rich