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08 CRF450R Milky Engine Oil

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Just noticed my engine oil is now milky and im losing coolant from the radiators.

 

Note - I have recently just rebuild top end and done 8hrs on it since, and now ive just noticed this.

Wossner Piston , Pro-Seal Gasket Kit

 

Any thoughts as to testing to find cause.

 

Im picking either the gasket is blown somewhere or maybe the head or cyclinder is warped, possibly a water gallery could be cracked .

 

Any help is much appreciated.

 

 

 

 

 

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Leak down tester will help diagnose it. If you dont have access to one, id pull it down and replace the head and base gaskets with OEM ones, and see what happens.

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Pop the radiator cap off when the bike is cold and start it. If big bubbles are coming up through your coolant looking down your fill hole then that's a deal give away your head gasket is blown. Milky in the Trans side is normal and means the basket is notched usually. When coolant is in your engine side usually when you first take your drain plug out the coolant will come out first.

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When you took your head off did you drain your coolant first? Cuz I've done that before and it drained a bunch of coolant into my engine so I drained it all did and oil change started it up got it all mixed around and then did another oil change and it hasn't been milky since!

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Update

 

I have pulled head off and noticed head gasket slit acoss two water galleries, and then noticed the green coolant on top of my piston.

Obviously the coolant was leaking through this gasket and going into the combustion chamber and passing through rings into the oil.

Ive ordered oem cylinder and head gaskets they should turn up today so i will install those tonight.

 

Heres a question what does everyone here use to prep head and cylinder surfaces for gaskets. Ive been told very fine wet and dry sand paper on a sheet of glass

and rub the head over the flat surface helps to find if the head is warped.

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Pop the radiator cap off when the bike is cold and start it. If big bubbles are coming up through your coolant looking down your fill hole then that's a deal give away your head gasket is blown. Milky in the Trans side is normal and means the basket is notched usually. When coolant is in your engine side usually when you first take your drain plug out the coolant will come out first.

 

I'm not getting any milky looking oil that I can tell (gonna throw a dip stick in there later), but Im losing some coolant through the overflow tube (through the bottom of the bike), especially on high revs. When I popped the cap, its almost like what you described, with the coolant sort of bubbling up, and then coming through the over flow hole and down the tube. Its seems to have tappered off now that the radiator isnt completly full. Im confused man.

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I'm not getting any milky looking oil that I can tell (gonna throw a dip stick in there later), but Im losing some coolant through the overflow tube (through the bottom of the bike), especially on high revs. When I popped the cap, its almost like what you described, with the coolant sort of bubbling up, and then coming through the over flow hole and down the tube. Its seems to have tappered off now that the radiator isnt completly full. Im confused man.

I'm not exactly sure I'm following you here.

The coolant in your radiator is only going to hold up to the top of the fins if your looking down the radiator fill hole. Shell spit out anything over and that's normal.

Now if your gathering tube is collecting a inch worth each ride or your oil has water in it then you have a problem. I think your good and just over thinking it unless I'm missing somethin. Small bubbles are normal but big bubble/constant lots of air trying to escape is a problem.

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I'm not exactly sure I'm following you here.

The coolant in your radiator is only going to hold up to the top of the fins if your looking down the radiator fill hole. Shell spit out anything over and that's normal.

Now if your gathering tube is collecting a inch worth each ride or your oil has water in it then you have a problem. I think your good and just over thinking it unless I'm missing somethin. Small bubbles are normal but big bubble/constant lots of air trying to escape is a problem.

 

Hey, thanks for the response. I think (hope) you're right about over thinking on this deal. The bike (08 KX450) is new to me and yesterday was my first day out on her. And yeah, I had the coolant topped off above the fins, so good call, I'm just learning these little things. I just replaced the water pump bearings, seals and shaft and I filled it to the very top afterwards. I'll continue to monitor the coolant levels and oil.

 

Thanks again for the insight and peace of mind.

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The coolant needs an air gap for expansion inside the rads when it gets hot. Leave about 10mm of space below the filler neck in the rads and it shouldn't blow the excess coolant out. But it'll self level even if you don't.

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