pressure building in oil tank

[Nate105]

hey guys,
I was wondering I know someone thats is have a problem. he gets pressure building in his oil tank what would cause this. he told me that if the dipstick is not threaded in that it would go flying. please let me know thanks

[JOHNDOE83]

I also have had problems with pressure build up and oil foaming, it only happens sometimes and other times it works fine.

I dont know the cause but I have noticed that it will be like that then clear up and fine.

I havent had any motor issues and have had this motor with these 2 issues since Ive owned it.

Maybe its because im using 5w30 sometimes, but I think its happend with 10w30 and 20w50 also but I cant be held to that cause I dont really remember if it did or not.

I wish we can figure this out?:confused:

[mxquad53]

do you still have the crankcase pressure problem too?

[Nate105]

no I fixed that but this problem isn't for me its for my friend. his 400ex does it all the time it doesn't go away he has pressure in the oil tank every time he runs it

[Rip_Tear]

have you changed oil filters and check the filter on the oil res(tank) and possibly the screen in the crank case. I'd say there has to be blockage somewhere.