Ok guys I have a problem.. my low oil pressure light keeps coming on after driving a short way, once I stop at a light or stop sign it resets and then comes back on. I also noticed I cant take the oil fill cap off when the engine is running. when I pull the dip stick out I can hear a lot of vacuum sound. and I can feel the vacuum when I pull the dip stick. so are these related? and is the crank case supposed to have that much vacuum? thanks for the help