Cummins 855 oil in coolant

Bob · Oct 4, 2013

Looked at a Versatile tractor today, for a neighbor... Cummins 855, turboed, NON aftercooled...

Has been running well, suddenly started using oil... 2.5 GALLONS in a short afternoon.

Figured out it's dumping it overboard, out the coolant surge tank pressure cap/overflow tube.

Besides oil cooler "O" rings or a head gasket failure between the rocker arm lube port area and the cooling system, what are the next most likely scenarios?

Crankcase oil looks OK... no foam or froth on the filler cap or dipstick. Will loosen the drain plug tomorrow and see if there is any coolan t in the "basement".

504-1 · Oct 5, 2013

Bad oil cooler, used to happen on the old 190hp after a million miles or so.

mite-help · Oct 5, 2013

yes-oil cooler bundle/O-rings. repair & flush cooling system with dishwashing deterg- sometimes will transfer a small amount back to oil while cooling system pressure is up after shut-down but not likely.

MARK ROBKE · Oct 5, 2013

Need to replace oil cooler and all it's seals. Oil pressure is higher than coolant pressure so when the cooler fails oil goes into the coolant. After the replacement, fill the cooling system with water and add Dawn dish liquid, maybe a pint or so. Run to operating temp and drop the water. Repeat several times as needed then just use water several times. Then fill with coolant and run it. You may still find oil at the fill / rad cap, but if it is not overflowing, its just residue. Mark

Frank 41 · Oct 5, 2013

I had the same thing happen to my 310 Steiger. I put dish washer soap in to clean out the oil. I DID NOT check the anti freeze that winter. Went into the shed and heard a dripping. It cracked a housing below the thermostat housing. A freind told me, "how can some one so dumb, be so lucky". They usually crack the block just above the starter. So don't do what I did.

guido · Oct 5, 2013

Hello bob,

The oil cooler is one source for coolant in the oil. Head gasket? PROBABLY NOT. Another source would be the cylinder liners or the seals. If the head gasket was bad, you would be building up radiator pressure, that is how they usually fail.

Guido

guido · Oct 5, 2013

Hello bob,

I reread your post, it sounds like IT IS the oil cooler "O" rings or the cooler itself. Oil pressure being greater the water pressure lets the oil go into the cooling system. If you find water when you take the oil plug out THAT could be the liners,

Guido.

55deere70 · Oct 5, 2013

You are right Guido, oil in AF often the oil cooler...AF in the oil is often liners leaking although I had a Cat 3406 that put AF in the oil through a bad water pump. I was relieved with that news.

guido · Oct 7, 2013

Hello 55deere70,

At least you were not relieved of your money!
Will see what bob will post

Guido

Cummins 855 oil in coolant

Bob

Well-known Member

504-1

Member

mite-help

Member

MARK ROBKE

Well-known Member

Frank 41

Member

guido

Well-known Member

guido

Well-known Member

55deere70

Member

guido

Well-known Member

Similar threads