Need help!!

Oh having some issues with the truck i just bout. woke up this morning and founf oil under my truck. I open the air box and bam oil was in there. So I changed the PCV valve and the Gommet(I think thats what its called). Well The truck has 136,000 on it. The motor was overhauled at 130,000. SO when i looked in the hole the PCV is in one the valve cover it was full of gunk. So so it led me to belive that the Gommet was letting air in a not letting the PCV valve work correctly. yes i shook it and the old one still rattles the check valve portion. So i put a new one in anyways and changed the gommet as well. So now i am worried about this sludge. I am thinking about putting a quart of ATF in the engine oil to clean it out. What do you guys think. Also the truck smoke a little blue when i start it from cold and i think this is what is was comming from. I think after i run this a while the blue smoke on start up will go away after the residual oil is burned up. I hope it is becuse the motor was suposivley overhauled and it is clean so someone did some work on it. I also bought some Full senthitic 5-W30 for it as well but i am holding off becuase if i flush the more with ATF i will use the oil it has in it then let that out then put the new stuff in it.

 

I could be wrong but if you are having blue smoke your plugs may be fouled as well. If so oil is getting past the seals.