routed (factory) pcv system . This is not uncommon and most people fix it by doing the pcv reroute found in the auto_faq . By looking at your previous posts it looks like a rebuild is in order and the root of your low compression will surface at that time. Even if it is a bent valve on that cylinder , the compression on all the other cylinders is not that great and you may want to consider a rebuild anyway . I would assume that bad blow by from a bad cylinder would only increase the amount of oil being sucked into your plenum .