Milk color oil?

I have a 01 YZ426, Not 100% sure on how many hours are on the motor. I know it hasn't been opend up befor, as I know both owners of the bike. Today after I got done riding I noticed the oil that was dripping out of the valve cover hose was looking a little milky. Today would have been the last ride befor changing out the oil. Could this be the oil Breaking down or does it sound more like its getting water or coolent in the motor? The oil is a 10W50.

Thanks, Nick

It probably is nothing more than moisture getting into your breather hose itself. It's fairly common. If the oil itself shows no signs of the same thing happening, I wouldn't worry about it.

After I think about it, The bike did sit in the rain for like 10min (didn't know it was raining) the other night. I will drain the oil and see what it looks like. Thanks for the input.


Like gray said, it is probably just condensation. When you change the oil, if it comes out looking milky then that is a sign that water is in your oil, and you may have a problem. However coming out of the breather hose looking milky like that happens quite often when there is no problem.

Well spotted. Check the oil, as stated above. If it comes out milky start looking at things like water pump seals and so on.

...If (the oil) comes out milky start looking at things like water pump seals and so on.
The water pump seals can't cause it. If the coolant seal leaks, the coolant escapes into a gap between the oil and coolant seal that is open to the outside, specifically so that the oil won't be contaminated.

Well there ya go, learn something new every day! Ok, in that case, if you see milky oil, look deeper than the water pump seal...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now