What are the routes of entry for coolant in the crankcase?

 

head gasket, crack in the head/block,
if your oil cooler is ran through the radiator then there could be an internal leak inside the radiator allowing the 2 to mix. Not familiar with the 6.2 but these are the most common areas to check

 

I knew the head gaskets, but you bring up an interesting point, is there an water to oil engine oil cooler?

 

I looked at the Ford factory parts website and couldn't find a water to oil cooler.

 

For water to get into the oil, water can NOT and will NOT enter via an oil passage that has oil pressure.

Water under pressure leaking via gasket, crack, etc will show up as in the oil.

Generally oil under pressure will show up as oil in the radiator/coolant tank.

 

Good point of the oil under pressure. Has anyone else seen this issue with a 6.2? I am going to send some oil off for analysis, but the things I have noticed is, not low, but on the lower end of normal coolant level in the reservoir and some foam under the oil fill cap.

 

It is not uncommon to see moisture under the oil fill cap if you do not drive the truck often AND then only drive it a short distance where the engine doesn't fully warm up to burn off any excess moisture inside the engine.

Sounds like you do not have a problem but overly concerned with the coolant tank being slightly low. Which is ok to be some concerned but I think is normal expansion and contraction and loss of coolant in this process via the overflow.

 

my FIRST question.. where have you been taking your Truck for Service..??????

someone MESSED UP.. and mixed the fluids... I have seen this many times at the Quicky oil places..

oil pressure 40 plus
antifreeze, 15 max

oil pressure drops quickly after engine off
antifreeze pressure drops slowly... as it cools. even can make vacuum if air pocket is in cooling system.

 

I have owned the truck since new and have always done the servicing myself. Oil change every 3000 miles. Just noticed the film under the fill cap the last time I changed it.

 

 

I haven't noticed it on the dipstick yet.

 

Wait,,,,all this is about a film on an oil cap....

that is oil beat with moisture and air from the crankshaft........ pcv valve may not be working correctly... or driving in to much rain..
or a thermostat.. taking to long to get engine up to temperature

Sorry IF I miss understand you last statement....

want the real answer...... get a oil analyst kit ... then you will KNOW what is in the oil.. NO GUESSING.
Brownstone is a good one... but many on-line

I DID NOT mean to disrespect... LEARN....
please read my bottom line of my signiture..

look at this link
https://ford.oemdtc.com/1301/excessi...ty-f-250-f-350
.

 

Yeah, this is just over gunk in the fill cap?

Didn't the 2015 trucks have a problem with the baffling in the valve cover and PCV valves? I believe there was a TSB for it as well.

 

 

I had a problem with low coolant and changed the radiator cap since an old one can cause coolant to be boiled off...give that a try, it so far has helped