gray oil

14 replies to this topic
  • saca

Posted April 07, 2008 - 04:03 PM


Hi! I have a 06' yz450f I just check the oil and the color is light gray. somebody know why is gray? maybe water in it?. Thanks! Kris.

Yes! I was out this sunday in the rain and I did try to start it in the water. So maybe that was it.

  • Aka.Goose

Posted April 07, 2008 - 04:31 PM


Kris, I believe if you started the bike but didn't let it get up to normal operating temperature, the milky color may have just been condensation...

  • maximus128

Posted April 07, 2008 - 05:40 PM


sorry dude, sounds like a head gasket to me.

  • Aka.Goose

Posted April 07, 2008 - 06:21 PM


Well, yeah...If it was run up to temp, and was still like that, then you may have water contamination...Then again, may just be completely normal if it's been a long time since your last oil change (caused from clutch friction plate wear)...

  • hillclimbguy

Posted April 07, 2008 - 07:48 PM


I agree, if its a gray color, then might have some clutch plate material in it. If its black then its old and time to change asap. If it looks milky and the color of something out of a kids diaper then you have water or coolant in it and you have problems.

  • USED YZ426F

Posted April 08, 2008 - 03:36 AM


I agree, if its a gray color, then might have some clutch plate material in it. If its black then its old and time to change asap. If it looks milky and the color of something out of a kids diaper then you have water or coolant in it and you have problems.

+1. You should change it if it has been sitting in the bike all winter. Cheap insurance against an expensive failure.

  • Ga426owner

Posted April 08, 2008 - 06:27 AM


Grey colored oil is a sign that water is in the oil. Check the dip stick or drained oil, not what leaks out of the breather for color. Either you suxed water into the motor from the breather tube - aka crossing creeks or starting the bike in water/water puddle or head gasket is leaking. Drain completely - refill with fresh oil check coolant level in radiator and see if grey continues

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  • chris142

Posted April 08, 2008 - 06:37 AM


If you let it sit a few hours some of the water will settle to the bottom. Pull the drain plug and see if it looks like antifreeze or clear water.

Antifreeze and oil will tend to stay mixed while clear water and oil will seperate eventully.

I'm not familiar with this bike. Could the water pump be leaking coolant into the oil? I think if it had a bad headgasket that leaked that much water into it you would know it.

  • saca

Posted April 08, 2008 - 05:12 PM


thanks! kris

  • Fabwiz

Posted April 08, 2008 - 07:40 PM


Is the oil level higher then normal? You can go to NAPA or other parts store and pick up a block check set up for pretty cheap, it an automotive thing but will work on bikes as well. Follow the instructions to see if you may have popped a gasket.

  • chris142

Posted April 08, 2008 - 07:43 PM


If it has enough antifreeze in it to turn the oil grey the radiator will be low/empty. Have you been adding anything to the radiator?

  • saca

Posted April 09, 2008 - 07:01 PM


No I have not. But I was out after the rain so maybe the water got in from the greek.

  • saca

Posted April 09, 2008 - 07:03 PM


Yes it was higher. But the coolant is the same.

  • SAGringo

Posted April 09, 2008 - 08:51 PM


my oil has looked like crude every time i have changed it since it was new. a guy at my local shop says he runs belray thumper oil (orange) and it comes out the way it goes in. well he must've put a watch on his bike instead of an hour meter because i do mine every 3 hrs and it always comes out looking pretty bad.

  • Ga426owner

Posted April 10, 2008 - 04:42 AM


THe oil will get darker as it gets aged and contain fine particles from clutch and motor....all normal
Grey oil however is water infected oil
check the oil filter for dirt particles and clean(note how much material is in the filter), replace oil - each hr /2hr of riding - it may take a few oil changes to get the oil back to normal color. I have found (thanks to GreyRacers Advice) that adding marvels mystery oil helps to dissapate moisture.

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