Milky Oil in Fill Neck

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Jun 25, 2002
I own a Dodge Pickup. Does anyone know how "milky oil" is making it's way into the fill neck?
If it was just a moisture issue, wouldn't we see condensation in the baffle area. The milk appearance tells us that the moisture is getting whipped up into the oil. Could it be the airator's that mist the oil coming into the head for the upper valvetrain components?

It just strikes me as odd seeing how you never see any milky oil on the dipstick, or in the oil that comes out of the crank case or filter. As far as I know, no one that has done the HO cam conversion has noted any foamy or milky oil in the top end either. Does anyone have any ideas on how this milky oil is being produced?
Other Comments
Red, I'm pretty sure there's a TSB on this involving a new cover & baffle. Check some of the Dakota/Ram boards or hazard a dealer call.

I have two fords and a chevy that get this milky stuff in the fill neck. No fluid leaks, only condensation. In all three cases, the fill neck is elevated off the valve cover and is generally the "high" point in the oil system. The heated condensation in the engine rises to the high point, which tends to run cooler since it is elevated over the valve cover, has airflow over it, and is not generating any heat. Thats where it ends up as the milky white fluid. Its never been an issue in any of these vehicles, and two are over 150,000 miles, the other almost at 100,000.
I agree with MNgopher, also, check all the breather tubes/pcv valve....make sure they are all "breathing" as good as they can, helps with pulling vapors...
I agree.

My F-150 has a moisture problem in the filler neck only and only during the winter months. It never shows any emulsification on the drain oil, filter or analysis.
Just spotted this situation on my F150 5.4L at yesterday's oil change. Been colder than usual here (mid 20's at night) and doing primarily short trips. Will this emulsified stuff melt when it gets hot enough or should I run an engine cleaner through it?
Do you have the 4.7L V8? These things seem to generate alot of this foam. I've seen them with over a cup of foam in them.

My view is that the crankcase vapors travel up into the oil fill tube, then they cool off before exiting through the pcv valve, and cause the deposits in the filler tube. All new Dodge's with the plastic filler tube (with the pcv valve attached to it) have this problem. This happens more when you make short trips or during winter weather. The baffle hides the problem from your view but it is still their.

Here is a thread I was involved in regarding this issue :


[ January 28, 2004, 04:40 PM: Message edited by: SSlube ]
I get the same thing on my toyota 22re (1991 - 150,000 miles). winter months only. If I drive it about 40-50 miles on the expressway it will go away for about a week. I do alot a short trips in the cold.
Yeah, see that a lot. BMW 6 cylinder engines can be pretty bad on that too. It is basically condensation (water) mixing with oil making a white oil/water mix. Running your engine to full operating temp for a longer period (50 mile interstate trip) usually gets rid of this stuff even in the winter
It will go away by itself if temps warm up or the engine is heated enough during cold weather.

I just wipe out what I can when I check the oil. Its worked for me...
I see the smae thing with my 03 Protege5 2.0L
The hollow oil cap fills up. Seems to be after short trips in cold weather. Burns off after long trip. Good idea to change your oil if lots of short driving in the winter.
I've only had this once recently on my BMW when the thermostat was bad (November). Replacing it immediately cured things.
There's water vapors in your crank case at start up all the time. The blow by is full of moisture, and when the engine heats up it evaporates.

Problem is the fill tube is the coldest spot in the crank case so the vapors will condense there if you don't run the engine long enough. In the winter you have to drive much farther.

I watched for my thermostat open today on the way to work. It was -5 when I left. I drove a good 7 miles to the freeway and still not up to operating temp. I had to drive another 2 miles at 65 mph before the thermostat opened up. That's a long ways, and a good 15 minutes of drive time.

[ January 29, 2004, 07:15 PM: Message edited by: greencrew ]
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