Water in the oil....sort of

[Wetflow]

A buddy of mine keeps getting the "chocolate milkshake" emulsion forming around the filler on his valve cover. This has been going on for a few years. Oil pressure is always good. Every time he does an oil change the oil looks normal. He's not losing coolant. Has anyone seen this before or can explain why this is happening?

[mt-engines]

Its condensation.

Nothing to be alarmed about.

[dannobee]

He needs to let it get up to operating temperature so that the water vapor/moisture burns off. Oil temp specifically needs to come up.

[allencr267]

Does he also have 'gasoline' spitting out the exhaust.
Your location, not anywhere dry/non-humid is it, and likes to start it up just to move a few feet?
Thermostat? PCV?

Condensation.
DO RUN run/drive it unless it is going to get good & warm, minimum 10 minutes!

[af2]

Plumb it to the air cleaner and it will never be evident.

[Wetflow]

Thank for the replies

Does he also have 'gasoline' spitting out the exhaust.
Your location, not anywhere dry/non-humid is it, and likes to start it up just to move a few feet?

He has never mentioned any gas spitting out the exhaust.

We're just outside of Daytona which is pretty humid most of the time.

He doesn't just start it up to move it a few feet but he works very close to home. Maybe a mile or so. I guess that could explain it?

[mt-engines]

If there is steam in the oil, it's going to rise to the highest point in the valve cover or engine.. its really not a big deal.. if it drains out clean.. its clean.

Fresh oil rarely splashes into the filler tube far enough to clear out the milk

[Wetflow]

Fresh oil rarely splashes into the filler tube far enough to clear out the milk

It all makes sense now. I've just never had to deal with it myself.

Thanks again for the feedback.

[Roundybout]

With the short drive times, the oil is never getting hot enough to burn off condensation. The coolant temp can get up to temp reasonably quick. The thermostat sees to that. Even with the coolant at operating temp it can take a bit of time for the oil temp to get up there. It takes some load/RPM to produce some temp in the oil.

As long as the oil is changed frequently enough I wouldn’t worry. I’d also suggest at least a few times a week driving it either a bit harder and/or longer to burn of any accumulated condensation.

[FishFry]

Does he also have 'gasoline' spitting out the exhaust.

I have exactly this problem, but only on one side - what's the reason?

Frank

[lefty o]

Does he also have 'gasoline' spitting out the exhaust.

I have exactly this problem, but only on one side - what's the reason?

Frank

likely the same exact reason the op's buddy has moisture in his oil, condensation. i would almost put money on it, your car has a single exhaust that splits into 2 tips/mufflers at the rear axle(closest tip to the main pipe collects the water). drive longer distances to let the moisture evaporate.

[NewbVetteGuy]

Tongue-in-cheek:

"I like to run my SBC nice and COLD! Thermostats is for suckers, but if you gotta run one make sure it's no more than a 160F one!"
"Them PCVs is "emissions crap"; get rid of 'em!"

*Queue Chocolate Milk-looking oil and acid->varnish->oil sludge*


Adam

[RDY4WAR]

There's 2 causes for that.

1. Condensation - The difference in temperature between the cylinders and external engines causes the block to "sweat". That condensation causes water dilution in the oil and can collect in the valve covers and lifter valley.

2. Combustion - Burning 1 gallon of gasoline produces 1.033 gallons of water. Most of it exits the exhaust as a vapor though some of it inevitably condenses and seeps into the crankcase. This gets worse the richer the AFR. Engines on E85 is several times worse than pump gas when it comes to this. Methanol is exponentially worse about it than E85.

Water boils at 212°F. You need the oil to reach at least this temperature to boil the water out. Engines that are short tripped such as <5 mile drives where the engine hardly, if at all, reaches full temperature, as well as engines that are run cold such as a 160°F stat, are prone to this issue. The oil doesn't get hot enough to boil out the water and it just keeps accumulating.

If the engine has a 160 or 180°F stat in it, replace it with a 192-195°F stat. Drive the car under a steady load to get the oil hot. Idling will not heat up the oil sufficiently. The primary source of oil heat is hydrodynamic friction. (engine load) Put an oil gauge in it and ensure the oil gets in the 215-230°F range for at least 5 minutes before shutting it off.

Short-tripping an engine with a low temp stat is a worst case scenario for the oil. There's some oils out there that can suspend the water better, prevent oxidation better, and ultimately not sludge up (as bad) with cases like this. They're also $12-15/qt because that chemistry isn't cheap.

[rgalajda]

For my classic car I never start the engine unless it is going out for at least 20 to 30 minute highway drive.
Living in southern Ontario Canada, in the spring and fall I use a partial radiator blocker .
When it comes time to park it for the winter the gas tank gets filled to expel that humid air. Parked in heated garage.
When installing a thermostat , it gets tested in boiling water first to see the temp it begins to open and fully open.
I also tested my temp gauge for accuracy

[FishFry]

i would almost put money on it, your car has a single exhaust that splits into 2 tips/mufflers at the rear axle(closest tip to the main pipe collects the water). drive longer distances to let the moisture evaporate.

No, it's a real dual, but yeah it has been sitting for a year - so I guess condensation it is.
Glad to hear that.

Frank