although my engine is different (4.2 i6) i had the same prob so when i went o buy a pcv they told me that 2.5s dont come with them, well mine did and the problem wasnt the pcv, its just blow back from the engine. mechanic said it wasnt too serious as long as i kept the oil level safe. he said it may be a bad ring or valve, and that it was a pretty common thing in jeep engines and also older engines. i just took the stock breather off along with the hose from the pcv and reattached it to where the hose came out of the breather so that eliminated the oil in my carb. you may have to do something different since you dont have a pcv.