Milky antifreeze

[engineer233]

I have a small problem to say the least. I have checked the antifreeze a couple of weeks ago to check the level. Tonight I opened the radiator cap and saw the antifreeze is now milky in the reservoir tank. The radiator seemed not to have any in it yet . I then checked the oil. It was ok. The NHC-250 is new to me as this is my first 5 ton. It is a M923. The truck holds 80 - 90 psi oil pressure at idle and around 100 -110 at highway speed. Is this too high and could cause this problem? How does oil get into the water? Do these motors have a common issue causing this ? Any advice or ideas at this point would be great.

 

[73m819]

OIL COOLER, number 1 thought, head gasket number 2 thought

 

[swbradley1]

I have heard rumors about the head gaskets on the 250s being a problem and since I have a bad one that is my first thought. But. I'm not a diesel mechanic either.

 

[engineer233]

How is the best way to check to see which one is the problem ?

 

[rosco]

Probably the oil cooler. Swap it out. completely drain the cooling system & flush it using a box of the non-frothing dish soap. I can't think of the name of the soap - its used in dishwashers though. Put the box in the system and run it for an hour. Get it good and hot. If its not clean then, do it again.

 

[maddawg308]

Next time you get coolant at the store, don't get the 2%, get the skim. That will fix you right on up.

 

[rosco]

You said it runs good, etc. No outward signs of leaks.... The oil cooler tends to be much more problematic. Do the oil cooler.

 

[Ferroequinologist]

I had the EXACT same problem with my XM818. It is the oil cooler for sure. Not a bad job, and I recommend replacing the hoses while you have it all apart.

The cooler itself is harder to come buy. And a little pricey. I have pics at home of my change out, I will post them here later when I get off work.

 

[engineer233]

Thanks that will be very helpful. I done some checking and found used coolers from $300-$800. They are kinda pricey. This seems to have just started so I hope I have caught this before it causes another problem.

 

[Ord22]

if it was the headgasket, you will have compression in the coolant system. meaning, the compression from the piston will push the coolant out through the resivior from where the blown headgasket is. you will lose coolant not coolant going into the oil. take the cooler out and put air through it and should see where its blown at. you may have to rig up something to check it. all i'm saying is, you would want to make sure.

 

[engineer233]

I like the idea of taking off the cooler and pressurizing it with air. I will try this on Thursday evening. Do these have any orings in them ?