oil in coolant

[88r]

I have a question that maybe one of the motor experts on here can help me with. I have a 04 450R with a 96mm 13:1 JE piston, head has been ported, kibblewhite SS valves, stage 2 hot cam. The quad runs great and has never over heated in fact the fan hardly ever comes on, the over temp light has never came on.

The problem is I have oil in the coolant no coolant in the oil. It is engine oil because it was low after the last time I rode it. If the coolant was in the oil I would suspect a water pump seal or head gasket. How can oil get forced into the radiator that is under pressure?

[MR4Engine202]

thats about the only thing i can think of is the seals from the water pump???

[d3ktrix]

If the seal on the water pump was bad it would dump the coolant out of the weep hole on the bottom of the pump housing or into the tranny oil.

I don't think a bad head gasket would cause oil in the coolant unless your rings/valve seals were REALLY shot.
Bad head gasket normally just causes the coolant to overflow/puke out.
And/or coolant to run down the cylinder into the oil.
But I doubt enough oil is getting up past the rings while it was running to get into the coolant, the bike would smoke like crazy.

If your getting too much crank case pressure from a clogged vent line and/or the base gasket is bad I would think that could pump oil into the coolant.
That is just a guess though.

Also a crack somewhere in the top end maybe.

[88r]

Thanks d3. I will check out the breather and base gasket. I was thinking the same thing about a crack. Think I'll pressurize the cylinder befor I pull it apart and see if I can find a leak into the cooling system.