Its probably condensation, from water or moisture getting into the crank-case. Maybe from an ill-fitting dip-stick cap, or moisture finding its way into the engine.
If you have changed the oil recently, i don't think there is any worry, but if it is from last year--better get some new oil in there!
By: Rustyj

As said, its from water getting in the oil.
It is possible to flush the engine to get it all out if you are concerned, but if you have fresh oil you should be fine. You could force a bit of rag down the dipstick tube to clean it up a bit.

Just to cite another way moisture can get inside the crankcase. Moisture is a by-product of combustion. Some combustion gases will "blow by" the piston rings (that's why it's called blow by) during operation, especially during the cold start and warm up period. Once the gases have "blown by" and are in the crankcase, the thrashing of the moving parts helps to mix them into the oil. This small amount of moisture (water vapor) is usually driven out of the oil when the oil warms up (if the engine is run long enough for that to take place, usually around 1/2 hour is sufficient. What is happening in the long dipstick tube is: The water vapor is lifted up into the tube (hot vapors will rise into cool space) because the tube projects away from the metal engine and so the tube is always being cooled by the ambient air (and I suppose you are using this machine in a "cold environment"). The water vapor then cools and condenses on the interior surfaces of the tube. This process of water vapor being lifted into the tube, and the consequent condensation continues even after the engine is shut off (because the last bit of blown by water vapor is still in solution in the oil and hanging suspended when the engine stops). The process of condensation will continue until the engine is cooled below the temperature at which water can be driven out of the oil. A little bit of milky streaks on the dipstick is no cause for alarm. Now that you know about the reason, you may want to change the oil about every 6 to 8 hours of use instead of the typical 25-50 hour interval used by most folks (in regard to "summertime outdoor power equipment) (My $.02 opinion)

Very good, Mownie! Thats the best explanation i've seen on the subject!
Rustyj

My new CC LT1050 had that creamy white substance in the dip stick tube and on the dip stick also. The mower had less than an hour on the meter. Cub said it was condensation caused by shoppers at Home Depot starting the engine for a minute then shutting it off before it warmed up. They suggested I change the oil and they sent me two oil filters for my trouble. No more problem since then.

Good explanation mownie.

Ray

I have seen that on my Ariens 9 hp Snow King engine dipstick since I got the machine three years ago. It rattled my cage the first time I saw it, but after hearing about this being a fairly common thing, it no longer bothers me. Charles Ranheim

I have a question .
Thoses of you that have experienced the "milky oil" ,are your machines stored in a cold or warm area ?

Thanx for all the insight guys. I kinda thought it was moisture related and more to the point what mownie has sais so well. again thanx. What had me worried was the fact that this machine Ariens Classic was bought used (2001 year) probably well used but doesnt look it. And that since I became the owner this fall has had three oil changes. The mobil 1 synthetic is whats in there now.

Just to make sure that all readers understand, we are talking about seeing moisture and milky stuff ONLY inside the dipstick tube, on the dipstick and the area on the inside of the dipstick tube cap/seal. Also note that the subject engine is AIR COOLED. If your engine is liquid cooled and the engine LUBE OIL ITSELF begins to have a grayish cast to it, or begins to look like a chocolate milkshake, consider that as an indication of coolant leaking into the crankcase. If you have a liquid cooled engine and see the oil turn to something resembling the above descriptions you should find the cause ASAP. I just wanted to make sure you understand that NOT ALL indicators of "moisture in the oil" should be ignored or tolerated.

I have to agree the "Milky substance" collects in the dipstick tube, and ends up on the dipstick when it is unscrewed and pulled out of the tube. I can see how the condensation can occure in the long dipstick tube that is exposed to freezing temperatures most of the time, while the rest of the engine is hot. I use conventional oil myself. It was interesting to note the same thing occures when using Mobil 1, as indicated in the initial post.

Charles Ranheim

In the old days we would have had plenty of fun with a thread subject like this.

Yep moisture. My friends nissan pickup had a ton of that when his timing chain wore a hole through the water jacket.

Many years ogo,my old aircooled Volkswagen car,and my Corvairs as well had this "white goo" year around.99 % ofthe use was short runs.Take them out for about a half hour at 50 to 60 MPH cleared that up.tbk

You have WHAT??? on your dipstick ... Shame on you!

This is an interesting thread ... Many years ago I inherited my fathers Mercury Marquis. It had a similar problem where the white sludge was building up in the oil filler tube on top of the valve cover. With a flashlight  I could see this was getting ugly down in there in the area of the valve gear as well.

(( I also had a similar experience with a dodge van  and I used the same procedure to cure the same problem. ))

After keeping my eyes on the radiator I was able to determine that I had no leaks in the coolant system.

HereÂs what I did to both vehicles  the oil filler caps in these two vehicles were black plastic. I took a 1/16th drill bit and I drilled 3 holes through the top of the oil filler cap and down through the bottom of it also. I positioned these 3 holes in a triangular arrangement and tried to avoid drilling through the printed words on the cap  so that my modification would not be obvious to any potential buyers down the road.

How did it work? Well it actually worked rather well  I did not clean out the filler tubes and the white sludge eventually disappeared on its own (about 1-2 weeks).

HOWEVER
 I donÂt think this modification would be a good idea on a snow blower. Note that the filler caps (with 3 holes) were under the hood of my vehicles, they were not exposed to the rain or snow like they would be on a snow blower. As a snow blowers engine cools (rather quickly), it would surely suck any non-frozen water laying on top of the filler cap down into the filler tube/crankcase.

 This modification might be OK on a garden tractor if the filler tube/and cap were well hidden under the hood of the mower.

Dave

Any additional "breather" or crankcase ventilation provisions on OPE will risk deafeating or modifying the "crankcase pressure pulse" that operates the fuel pump on engines so equipped. The best approach is to accept that water (as a combustion by-product) is going to appear under certain conditions but does not constitute a problem if it appears in a remote (away from heat) location on the engine. Avoid running the engine at all unless you are going to "work it" long enough to get it warmed to normal operating temperature, and change the oil more often on OPE that is normally operated in cold weather conditions, especially if the engine is "air cooled". Your typical air cooled engine in OPE DOES NOT have an automatic thermostat device to establish a MINIMUM operating temperature (unlike liquid cooled engines that do) and the operating temp of an air cooled engine is lower (sometimes "too low" to evaporate "all" of the water that gets into the crankcase as
"blow-by").

I have the same thing with the 11.5 Tec on my 2004 Ariens Snow Thrower. No problem. Just change the oil at the recommended intervals or end of the season. If the oil itself is milky it needs to be replaced ASAP. I had a 1952 Ford 8N tractor that had been left outside by the previous owner so some water seeped into the transmission case. The hydraulic/transmission fluid (5 gallons that served for both purposes )was milky but I ignored it. The hydraulic pump housing cracked during some subzero temperatures and had to be replaced.

Try some pennicilin, that usually clears it right up.