I recently changed my oil about 2 weeks/700 miles ago. I've always been somewhat **** retentive about "fluid levels" on my mechanical wonders of manmade technology ('96 Ram 1500). Saturday, I was checkin' the levels n all appeared okay, but my oil catch can wasn't. The dipstick was showing lotsa, grrrrr... I pulled the can off n it had about an inch of what looked like the proverbial "antifrz in the oil" look to it. Ovaltine, more than nestles, ya know? I went into auto...sailors language, spark plug removal, bore scope, compression gauges n recheckin' of the fluid levels. WTF, all normal, said I?!? Then I said to myself, "you moron, recent cold fronts, very humid air n lotsa short trips. The moral of the story, if you got a catch can n you got some chocolate yogurt built up n the catch can n nothing else seems rong, well... Hope this little tale helps someone else avoid lotsa wasted time n heartache.

 

I have a similar problem with the oil fill cap on my Hemi Durango. The fill neck and cap are all made of the same composite material the intake manifold is. Every winter I get the same effect because that section never really warms up enough to evaporate the condensation. I used to take it in to get the oil changed in the winter, but after a series of shops refusing to touch it because of what the oil fill cap looked like, I just started sucking it up and doing it in the winter too.

 

the catch can is doing its job.
I have seen the same collection of crud in some vehicles that run resonator boxes in the air intake. hot air from the egr meeting cold incoming air.