Some milky residue under oil cap..

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2001 acura integra 5spd with 91k on the odo.

So after 35k miles of owning my car, i finally looked under my oil cap and to my surprise i find little amounts of brown milky residue in there. My coolant is ALWAYS where it has been since i bought it at 55k. My temperature gauge is also very stable.

The car has never overheated and i performed a coolant flush about 78k. Coolant was done again at 81k when the timing belt was performed. When i FULLY flushed the coolant at 78, i used honda's 50/50 mix and filled the rest with distilled water(about 1/2 gallon)

Is this normal for it to accumulate like this? if not, what is causing this? The coolant in the reservoir is as blue as it gets and dipstick oil is never milky.
 
Condensation, most all cars do it to some extent in cooler weather. Check your PCV system to make sure everything is working properly. If the PCV system is clear, the best way to get rid of it is to get out on the open highway for about an hour and drive it.

Motor oil has emulsifiers in them that are intended to trap moisture and that is what you are seeing. They always show up at the coolest part of the engine, and that is right where you see it. You should come to WI and pull an oil cap of a car that never leaves the city limits. Looks like a milk shake.
 
^ thanks for the input. The PCV valve has less than 10k on it. Brand new from Honda. i feel better now!

i'll run a UOA for the heck of it in about 4k miles. Just did an oil change.
 
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I discovered this after the car had sat for a week in the garage and i drove it about 1 mile to get it to semi-operating temperature for an oil change(old fluid-amsoil 5w-30, new oil- 5w-30 synpower).

How long would it take for this to accumulate?
 
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Humid/wet weather makes a big difference.
Add this to short trips of not getting up to operating temp, and you can easily get the milky stuff on the relatively cooler external engine parts.
Like mentioned, double check you PCV system - not just the valve.
If possible, take her out for a good hot drive.
 
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