Ok, my 99 rodeo 4cylinder just started smoking today so I was just looking at everything to figure out what it was, I changed the oil and filter and while I was removing the air intake tube to get to the plugs easier I noticed that there was oil in it and in the throtle body, from what I can tell it is pulling the oil in from the small tube that comes of of the air intake tube and runs in to the valve cover, so I put the new plugs in it and started it without the hose on and sure enough it was spiting oil out of the valve cover and I could feel air blowing out, so my question is (WHAT IS WRONG WITH IT)?, I put it all bake together after changing the oil, filters and plugs and it smoked just the first time down the road, but it has stopped smoking for the most part, hopefully, is there supposed to be a pcv valve on there or in there or what, or is something broke?