coolant and oil mixed dripping at bottom of radiator

[medseg2003]

hello ,
I gave 2013 freightliner cascadia isx 15 .today i notice that i have a bad coolant leak under radiator its dripping like crazy. When i touched i noticed it s mixed with oil.
I check engine oil no water in it, i check coolant reservoir no oil in it, yesterday i had ultimate PM at TA shop, i don't know if the guy did some thing funny specially when he was trying to open the bolt down the pan he was tighten it instead of loosing it hopefully he didn't hit the bottom of radiator, i am not sure i don't want to blame him, also when checking the oil i find it overfilled way above the limits.
Any idea what can cause the oil and coolant mixed dripping bottom of radiator. Couldn't locate from where exactly it leaks thx so much

[Baco74]

maybe transmission oil going through radiator

[tree98]

I would degrease the engine and under the radiator the best you can and then pressurize you cooling system to 20 psi and let it sit overnight, fix all the leaks you find. Then run it for a few hours and look for oil leaks. You could have 2 separate leaks and they are just mixing somewhere on the outside of the engine and dripping off.

[Mattman]

Could the oil be coming out of the crankcase breather?? How much overfilled?

How bad of a leak? Won't take long for the coolant jug to start dropping the level.

[medseg2003]

about 1/2 inch over limit, and i add 1 gallon of coolant in 150 miles driving ,and it s gone already now it s below limits thx

[medseg2003]

(08-04-2020 )Baco74 Wrote:  maybe transmission oil going through radiator

You may be right because the mix of coolant and oil are still in red color not dark at all, i will not know it s mixed with oil if i didn't touch it with my fingers it looks just like coolant thx

[medseg2003]

(08-04-2020 )Mattman Wrote:  Could the oil be coming out of the crankcase breather?? How much overfilled?

How bad of a leak? Won't take long for the coolant jug to start dropping the level.

about 1/2 inch over limit, and i add 1 gallon of coolant in 150 miles driving ,and it s gone already now it s below limits thx

[JimT]

first things first, find the location where coolant is leaking and fix that! 1 gallon in 150 miles is serious and could get much worse at any minute.

As tree98 said, the oil could be coming from somewhere else, such as the breather. If you're over full on oil I'd check your crankcase breather filter and see if it's full of oil. Drill it out or replace with a maintenance free filter. You don't want it getting clogged up with oil then not venting pressure from the crankcase. Being a little over full shouldn't hurt. make sure you check it cold on level ground. I know mine can vary in reading up to 2 quarts depending on the angle of the engine and how long it's been sitting.

If you're not seeing oil floating on top of the coolant reservoir then it's a good chance that the oil is coming from some other location and mixing externally.

[Waterloo]

Maybe the oil cooler... Wasn't there a TSB on those?