I have a 91 civic HB standard, 1.5 sohc. Was smoking very badly but intermittently. Was told it was the head(valve seals). Put on a rebuilt head. During the process found the PCV line completely blocked with dried sludge. Replaced line and pcv valve. Did not however check the metal box on the side of the block to which the pcv line is connected. I assume that is a baffle to let the lower end breath while keeping oil out of the pvc line. Anyway, car started right up, ran very smooth, the idle was a little fast. Within a few minutes it puked oil out either the front main seal or pan gasket. Checked the operation of the pcv valve by squeezing the line, does not appear to be working. Also noted that when I take the oil cap off the idle changes. First question is what is the metal box on the side of the block that is connected to the pcv valve? If it is clogged up would it cause enough pressure to build up in the lower end to force oil out the main seal, or blow the pan gasket? The car does not leak oil continuously, only after the motor has been started a few minutes. Any help would be appreciated.