2000 yz426 grey oil out of breather hose

Hello everyone:

I've come across an odd situation on my 2000 YZ426F. I have grey oil coming out of my breather hose (on the valve cover). The odd thing is, my oil is perfectly fine. I would expect all of my oil to be discolored if I had a problem with my water pump or something grinding in my engine. I'll be taking a look at a few things in the next couple days//weeks, and hope to have a better udnerstanding of whats going on later. For now, anyone have any idea what can cause this? When I saw the grey oil I was initially very worried, and immediately changed my oil, and my oil was just as any used oil would be expected to be. I run full synthetic, no friction modidfiers etc. through the engine, and I've never had problems with it before. Is it possible theres something weird happening int he valve cover that is discoloring the blow-out oil?

Thanks in advance for reading this!


Atmospheric moisture is all. As you say, your oil would be visibly contaminated if the water were coming from there. It's pretty normal in humid climates.

Grayracer: As always you rock. I can always rely on you to clear things up!

Thanks again!

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