A couple days ago I took my 1999 F150 5.4 V8 (140k) out for a good snow bog. The next morning when I went to add oil I noticed a white, milky substance on the bottom of the oil filler cap. I changed the oil that same day. A couple days later, after some more snow bogging, the white substance has returned. I did not notice this when adding oil in previous weeks. It has been much colder as of late and I did work the truck pretty hard in 4-wheel drive. Please tell me something's not leaking into the engine. The coolant level seems to be normal.

Thanks
Matt

 

It's normal, just condensation. Happens a lot in trucks that aren't driven long enough to reach full operating temp and/or are driven in cold temperatures.

 

and i bet at least 20 more people ask this question before winter is over.

wipe it off and you'll be ok.

 

Romp harder.

Adrianspeeder

 

Yeah this comes from oil not getting hot enough to burn off the condensation as others have stated. Running the truck for longer periods of time usually helps this, but it seems to be due to the cold weather more than anything. I used to have a dodge that would do that even in the lame winters we have in tx. After swapping to synth oil didnt seem to notice it near as much.

 

Boats will do it as well over winter storage.

 

I dont want to scare you, but i think its a head gasket problem. I had same problem with my car not the truck. I hope that i am wrong! Its not cheap fix. unless you can change head gasket. Good luck.

 

nah, I have that all the time, its just from condensation. The cap vents, which is where condensation forms...

 

It could be but chances are it is codensation, one could run a comp. test if in ?.

 

Mebbe the oil you are using has a detergent in it, and what you are seeing is the suds that weren't rinsed completely.

Yuck, yuck........lol

Mine does it and I am up past 218,000 miles on a 4.6.

 

the detergents in the oil cause the oil and water to emusify, that is what the white stuff is!

moving to AZ usually solves the problem. of course when I fell in a 3 foot hole in a muddy stream on my dirt bike, i had the white residue on the dip stick. drained the oil and let the plug out for a week and still had the white stuff after changing oil. so i started the bike and let it idle without the dipstick. that got rid of it.

 

It is just condensation I have had the same issue with my 05 Scab in the winter. If it was a blown head gasket you would see oil in your coolant and the coolant level would low along with the milky residue on your dip-stick and oil-fill cap. But it never hurts to ask your local service shop for their eyeball on the situation, they may see something that you're not.