Sounds like too much blow-by, caused by weak or carboned up piston rings. Do a compression test or leakdown test to see if that is your problem.
Here are a couple things to try if it is the problem. They can both help in the case of carboned up rings, but not in the case that they are just plain weak.
1) Sounds retarded if you've never done it, but it works. Take your air filter tube loose from the Throttle Body. Start the Jeep and rev it up a little at the TB and pour/spray small amounts of water into the TB. It will actually kinda steam clean the carbon from the ring grooves. Again, SMALL AMOUNTS at a time or you could hydrolock the motor, screwing up lots of stuff.
2) Get some Stoddard solvent and add about a quart to your engine oil and start it up. Let it idle for a while (20-30 minutes) and then change the oil and filter. The solvent will loosen up the carbon and free up the rings.
If it still does it then it means the rings were just weak. Time for a rebuild.
