Yellow sludge inside oil fill cap normal?

Its caused from Moisture build up from short trips.

 

so its moisture and oil mixed together?

 

Yes

 

Putting some Lucas Oil Stabilizer in at every oil change will stop that.

4.0 v6 takes 5.5qts, buy 5qts of your choice and top off with Lucas.

Also helps with the tacoma tick.

 

OP. You're ok,but clean it out with brake cleaner.
Don't feel bad,for a new truck I change my oil at 1k and 5k.
I use the synthetic Lucas additive with full synthetic oil at every oil change to help with condensation and engine smoothness.

 

I wouldn't add any additives to the oil. Run the synthetic and change every 10,000 miles or 12 months.

 

No thanks.

 

Funny that you mention this...my wife drives an 09 Jeep Liberty and I've used Mobil1 in it since the first oil change. Her drive to work is about 10 miles and I used to see the yellow gunk in the cap. At some point I started throwing in a bottle of Lucas synthetic stabilizer every change because the motor sounded like a sewing machine clacking away. The engine noise is significantly reduced and I just realized when reading this post that I haven't seen the yellow gunk since.

 

Bumping this because it happened to me today. 2015, 75k miles . I change every 7k with synthetic oil and this is the first I've seen it.

 

How long is your daily commute? With the colder weather short trips dont allow the engine to burn off the condensation which results in the milky goo under the cap

 

I work from home, but I do have a lot of 30 minute trips around here.

 

Its the short trips with the weather that creates the condensation. You need to run it.

 

Only times Ive experienced the crap under the cap was when using Mobil 1. Go figure.
Just checked it tonight...nada. And its been short tripped all winter using Magnatec.

 

I never experienced this until i moved to Monterey where the temps were always in the 50s, 60s, foggy and i lived a mile from my work, so drove 2 miles total most days. Then i moved back to phoenix where it's warm, dry, and had a lot longer commutes, causing everything to go back to normal.

 

I use Penzoil Platinum. I noticed this on mine a few months ago and since I've been driving from southern Indiana to Illinois and back on the weekends, it's gone away.
I wouldn't sweat it.