When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It's happening because oil & water vapor wafts up from the engine and gets cooled off in the relatively cooler cone, due to it sitting high off the engine.
We'll see what happens but I think insulating it will probably make the problem worse. The fact that it's plastic already makes it an insulator. Would be better if it were made of metal to absorb engine heat. I saw the same effect on a lesser scale under the plastic valve covers. It's the reason why I never run conventional or a cooler thermostat on this 4.7 of mine as you can't monitor or clean it out from there and then you have two ingredients for sludge.
yup, went to the store earlier, 12 mi rt, got home, pulled the Dak in the garage and popped the hood. 30 min later went out to pop the cap, fill tube pretty cold against a warm engine. pulled cap of and sure enough, condensation dripped off the cap. have to go back to store, will run it some so that by eod tomorrow will have approx 100 miles on it. temps are stable, storms rolling thru from time to time, typical weather.
if this does not work, i will find another potential solution and try that. might be a combination of things. bottom line, it will not stop by itself so it requires intervention
Just checked mine. I last wiped off the cap a few months ago. Haven't cleaned down in the tube since 2020 when I did the lifters. At the time I believed it was normal for the oil to flow down so slowly. It was clogged with black hard buildup. Oil goes down quick nowadays. I do drive about 50 miles a day to work and back, so the oil gets heated up fully and water burns off.
Just checked mine. I last wiped off the cap a few months ago. Haven't cleaned down in the tube since 2020 when I did the lifters. At the time I believed it was normal for the oil to flow down so slowly. It was clogged with black hard buildup. Oil goes down quick nowadays. I do drive about 50 miles a day to work and back, so the oil gets heated up fully and water burns off.
Huh... just noticed this, your cap has a vent hole in it, mine appears to be plugged... going to have to investigate that...
Good eye! I never even noticed that. Gonna stick a carb cleaner straw in there and blow it out when I get home. Now I don't know about yours, but my cap is hard as heck to pull off if I tighten it even a little bit. Maybe I'm just getting old and weak. Have tried greasing the threads, etc. It helps temporarily.
That is too funny... my cap is the same way, I dont even bother with it by hand, I use oil filter pliers on it. Funny thing though, it is easy to remove after it has been removed for the first time. Makes me wonder if it is under pressure which is making it difficult to remove...
120 miles, no change in weather... wet & cold. Note the condensation ont he bottom side of the cap. No wipedown of anything, will let it ride and report back in another 100ish miles.