You had me worried because my daily drive is from the garage back out to the driveway and the mailbox, and then back into the garage. Pathetic, I know. So I checked my oil cap and it looks like this:Hi all, I've had my 2014 Pilot EX 4WD since new, and it has about 95k miles now. I just had a P3400 error, so I replaced the rear oil pressure switch. This did not solve the issue though. At the last oil change, there was some off-white sludge on the oil cap. I'm sure this is due to all the short trip driving I've been doing, and it's really cold here in northern Wisconsin. See below for exactly what my cap looked like. Anyway, I think the oil pressure ports are clogged due to this condition. How do I clean those ports? Was going to try an enginer de-sludger. Can i blow air or carb cleaner in that oil pressure switch port?
Yellow gunk under oil cap — Ricks Free Auto Repair Advice
I think what you're seeing is moisture condensation mixing with the oily film. When weather gets cold and the dew point drops, condensation will form on the underside of the valve covers (including the oil cap).