I took off the oil filter and see in the housing there is a small poppet valve. Is this the pressure relief valve? There was a small piece of gasket( or something ) and it seemed to holding it open. Could this cause the low oil pressure I have been having? There are 2 bolts that hold the housing in. If I take them out does the housing come out in one peice or are "things" going to fall out I can't get back in? Thanks for any help I'm under the car right now!