I just started my 05 challenger up for the first time this year and was letting it warm up before the oil change when i noticed that there is allot of pressure in the crankcase. If i remove the dipstick i get a nice little pop when the pressure is released and i cant even open up the oil fill cap or allot of oil starts splashing out. I just have never noticed this before and is it normal or is there something i should be checking. It has the 4-Tec SC motor.