White Gunk in Oil Filler Cap/Tube

When I did the first oil change I noticed white gunk on the underside of my oil filler cap and also at the top part of the oil filler tube. I figured it was possibly assembly lube that got slug up there by the timing chain. Now the truck has 21k miles and even though I've cleaned it off before, it actually seems to be accumulating. I check the oil frequently and never saw any red flags such as streaking in the oil from coolant, and my coolant level is holding strong. This is concerning me because on my most recent oil change last week I didn't pull the drain plug. I used one of the better devices to suck the oil out through the dipstick. The vacuum device worked well and got all the oil, but I saw a couple of pieces of sludge get sucked up the tube. I've always been a fanatic with maintenance and never exceed my oil change intervals. I do not haul, tow, or plow with the truck and it's never overheated. Could I be cooking my oil somehow? Please help. Thanks.

 

I think the white gunk in your cap is condensation mixed with oil causing it to turn that color. I have that on my cap also. The first time I saw it I was concerned but every time I drain the oil it looks good.

 

yeah ive had it a couple times. its no big deal. ive heard it can happen from driveing only a couple miles every day.

 

Its condensation. Cold weather, the long plastic fill tube and short trips make it worse.