I have a 2004 F150, with 200,000 miles. My daily commute is about 20 miles. I add a quart of oil at 3,000 miles, then get an oil change at 5,000 miles. I live in Atlanta, and it only rarely gets below freezing (if that matters).

This weekend, I removed the cap to add oil (I was a quart low), and found this yellow pasty buildup, the consistency of mayonnaise. There was no trace of it on the dipstick.

yellow goop where I add oil

I've found this question, which suggest driving it long and hot enough to clean out the sludge.

Is that it, or is something else going on? Thanks!

EDIT: Consensus from people I've talked to agree that this is condensation, more noticeable now due to cold weather and short trips. I'll clean it out and go for a drive, and then report back. Thanks!

1 Answer 1


That looks like quite a bit more than the linked questioner had.

I'd say head gasket failure, but if you only do short trips then it's possible that it's simply condensation. Take it out on the highway and let it get really hot.

  • 2
    If it's just on the cap, I'd suggest it's not head gasket failure. Your suggestion of taking it out on a road trip is a good suggestion. I'd also suggest cleaning the cap out, then checking it again after the road trip. Take it out on the highway for an hour or more to get it fully heated. Should clean out any residual of condensation in the oil. I'd also suggest checking for blow by, as at 200k miles this is a distinct possibility. If it's there, it could be introducing a lot more condensation into the crank case. Dec 27, 2017 at 0:54

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