I searched the forum and this problem has been seen. I got a kit for a block test that sniffs the coolant for exhaust gas. That showed negative for exhaust gas. I checked the radiator and coolant recovery tank and the coolant is not looking contaminated. I did a radiator pressure test on t he radiator and in about 20 minutes it dropped about 1 pound. Not sure if it is a leaky gauge or if there is a small leak(pumped to 20 PSI and dropped to 19 PSI). The oil does not look milky. I replaced the PVC valve but the old one ratted just fine. I put in a pint of Seafoam and ran the truck about a 100 miles tonight. When I got home there was moisture in the cap. I am going to change the oil tomorrow and take a good look at the oil. The truck has about 110,000 miles and has no DTC codes.

Every thing seems normal but the moisture concerns me. It has been cooler at night, about 35-45 degrees Fahrenheit and about 60 in the day.

I saw people say you can get this from short trips. Last week I went to Houston, TX and back pulling a small trailer. I came back home after 3.5 hours of 75 MPH driving and parked the truck. I came out in the morning and checked the oil filler cap and there was drops of moisture on the cap so it is not caused from short trips.

Any further suggestions. My coolant levels were full at the radiator and the recovery canister and clean. Puzzled!!! Should I be concerned?

 

It's condensation. Stop worrying about it. You should see a 4.7L oil cap and fill tube...sometimes a bunch of yellow goo forms in there.

 

This^^^ (and no **** about 4.7's lol, 3.7's too)
No, you should not be concerned. Oil in the puke tank? Choco milkshake in the sump? THEN you should be concerned. Oil fill is the highest point in the crankcase system. All condensation will ultimately end up there. Wipe it off and go on with life. What you read about short trips is that those can make it worse, where CONSTANT short trips and not getting the oil hot enough allows enough condensation to build up (because it doesn't get burned off) and sludge up the oil.

 

I’ll chime in and agree with the above. My ‘08 Ram 5.7 does it and so does the 3.7 in my Liberty. Another contributing factor is the fill tube being plastic, doesn’t transfer the heat from the motor the same as the metal parts and is usually cooler. Therefore with the temp difference, the moisture will rise and collect there.

 

Here you go....

https://dodgeforum.com/forum/3rd-gen...fill-tube.html