When the oil cap is off and engine running yu will hear the valves and the air pressure, anyway, yu need to be a little more clear. The rubber boot from the bottom of the spark plug wire shaft stayed in the spark plug tube on the spark plug?well first , i have had this problem before. I did take them out, but a diffrant way. But here wut yu need to do, the oil thats in the spark plug tube is from the cam cover gasket. Where the cam cover opening meet the spark plug tube there are an almost oval rubber seal that seals the area between the cam cover and the spark plug tubes.They usually dry up and oil will dribble into the spark plug tube. . get a cam cover gasket set and it will have the spark plug tube grommets with it.the rubber boot, hmmm take a long enough but thin flat screw driver and try to dislode and unstick it from the spark plug(happens alot, the plugs if have been on for a while heats up and the boot sticks to teh ceramic portion of the plug)once yu have gotten it to unstick take a wire cloths hanger ,cut off a 7 inch straight part. on one end make a small half inch hook style bend, that side yur going to use to fish the rubber boot out, sorry i dont have another way, but i got it done that way, if it was a mitsubishi or toyota yu could have just unscrewed the spark plug tubes after removing the cam cover lol