Moisture under the oil cap... milkshake

[BigDirie]

Hello everyone I'm new to this forum, I got some issues with my truck...2015 prostar with Cummins isx15 400hp...I got moisture under the oil fill cap....took to the dealer, they replaced heater core and water pump...I still got the same issue.. thanks everyone and I would really appreciate your help

[BigDirie]

And truck only has 259566miles...

[marek4792]

Is it cold where you are currently, any coolant consumption? Could be a whole range of issues, could be injector cups/bad cylinder head, egr cooler, air compressor, head gasket, oil cooler, maybe be simply condensation hence the first question I asked.

[BigDirie]

I live in Ohio it wasn't that cold till last week...Yeah little bit coolant consumption not that much though...

[tree98]

When is the last time the crankcase filter was changed? Could be condensation. Did the dealer do an oil sample to see if there is coolant in the oil and how much if there is? Sounds like they are totally clueless as usual.

[hhow55]

I would see if moisture is also in crankcase filter,on the underside of valve cover. Punch a hole in bottom of oil filter and see if coolant comes out.

[BigDirie]

I'm positive dealer knows the issue.. because I got 2 months Left on the warranty.... I took there couple weeks ago and they replaced water pump and heater core... those parts has nothing to do with moisture on oil cap... Crankcase filter has been replaced roughly 50k miles ago...as well I forgot to mention coolant reservoir has little bit bubbles in it and there is a steam as well..but dealer told me it's normal... Thanks everyone for the help...

[BigDirie]

Oil sample has been done too... they said it looks good!

[Running rough]

Ask dearler if it couldn’t be a low liner causing blown head gasket/ cracked egr cooler/bad compressor/ injector cups?