I have an 05 1500. When I take off the oil cap there is a yellowish milky substance on the cap and down the fill. Ive had diffrent answers and Im confused. I hear it could be the cap allowing moisture in, the head gasket, and the dealer told me it could be the pcv system. Its still under warrenty and I dont know who to belive. The dealer wants to charge me $400 to clean the pcv system. I thinks thats BS. Please help if you can. Thanks ahead of time.

 

Well, if it is from coolant you are obviously losing some into the engine. Any white smoke out the exhaust or even easier yet, is the reservoir low? That right there would eliminate coolant.

Do you use any oil additives in your enigne oil? Certain additives when mixed with certain oils(ie. Lucas, Slick50, Restore, etc..) will cause an oil to foam more than normal and will actually hurt your oil performance.

The bottom of my oil cap has a slight browning to it but I have had that happen on other vehicles before and therefore I wont worry about it on this one.


How many miles are on the truck? Have you kept up with regular maintenance? How often do you change your oil, are you due?

 

I change the oil evey 3000 miles with full synthetic. I have 31000 miles on it now. All hwy miles too. Never add anything to the oil. Coolant level is fine. It runs perfect Ive kept up with the maint. But that crap is starting to worry me.

 

Its probably just the oil foaming slightly, fumes condensing on the cap and slightly hardening. I wouldnt worry about it.

 

Or a bit of moisture in the system. The 4.7's like mine are notorious for getting just enough moisture to leave that same film on the fill cap. I wouldn't worry about it though. Might want to pull your PCV and see if it needs a cleaning though. Shake it and make sure you hear the bearing rattle back and forth.