There's Oil in my coolant, but no coolant in oil! 2007 VNL670 w ISX

Oil pressure in engine runs from 30 to 40 psi. Water pressure is much lower, so oil willl flow into water. Possibly oil cooler Had several Cummins do it. Cooler can be checked at radiator shop, and is the first thing to check.
Could be pitted liners, or O-ring on liner. that ain't good, but with that many miles might be.

that's trucking. Good luck

 

The oil cooler did not cause the blow-by. The blow-by comes because something is worn in the engine,( quite often the rings ) allowing compression gasses to get in the areas that lead to the area betwen the valve covers and the heads. That tube you speak of allows the gasses to escape and not build up in the block.Excessive blow by usually indicates major interior engine wear.

Are you certain the blow by is not water vapor ? Do drops of water condense and fall from the ground through the tube ? Thinking back, the answer is no. You said it did not use water.

Probably the oil cooler or the O-rings, or the gasket.

 

Glad you can work on your own engine. It saves a lot of money doing the work yourself. Hope it is nothing major. Please let us know what the outcome is.

 

to test where your coolant leak the Way I was taught is;
To remove the Oil filter & the Oil pan.
Then pressurise your cooling system.
If coolant leaks out the Oil filter head. our oil cooler is Leaking.
If coolant leaks into the Oil Pan area you have either Leaking Liner seals or Elctrolisye in a Liner..

I've never owned (nor do I intend to) a EGR Motor, so unsure of how to test your EGR cooler "insitu"

 

The oil cooler can cause both of the problems you have. The amount of oil in the coolant really points towards the cooler. The cooler has 1 or 2 elements, some piping & gaskets. Cummins has a test kit that allows you to pressurize the cooler assembly after you remove it from the engine. Sometimes the gaskets are the problem & the elements are fine. Look for a local cummins shop that can test it for you , save you from buying parts you may not need. For cleaning the coolant system, fleetguard has a product called Restore. Works well.

A word of caution while cleaning the engine block & cooler elements. Do not allow any contaminants to fall into the oil passages. Trash in the wrong hole can cause major damage to the engine.

Good luck

 

!st have oil tested for coolant at speedco or send off a test kit that you can buy at most truck parts stores,that will tell you if oil is still good an if head will have to come off because of coolant in oil the water will burn off an go out blowby tube like you are seeing?

 

Oil cooler is a known issue with the ISX. Test the EGR cooler while you have it off as well as it is most likely leaking as well. When you pull the oil cooler plate out of the block, make sure you are very careful while cleaning the mounting surfaces. Use plugs to block off the oil passages so you get NO debris in there. I have seen multiple cases of windowed blocks after sloppy oil cooler repairs. Replace the cooler(s), and reseal the cooler plate. if the EGR cooler has wetness in it, replace that as well. Get a gallon of simple green. Fill your cooling system with 1/3 of the bottle and the rest water and flush the cooling system 3 times at minimum. Rinse with water inbetween each flush. It is going to take a while to get all the oil mess out of the cooling system.

 

There could be only oil cooler ,head gasket or cylinder liners. change oil cooler , flush coolant with detergent couple times. If that does help,then will have to check head or liners .. and thats gonna be expensive.