Does anyone know which parts I need to get rid of blowby?

The other day I decided to check out the inside of my air box and noticed I had oil in my air filter. I searched a bit, and gathered that blowby is the culprit. I also think that this is the cause of the oil that keeps showing up on the top of my valve cover, though I'm not sure about that. I saw that everyone was suggesting this site for gettin rid of blowby. Naturally I went there and wrote the part numbers down with the intention of going to a Jeep dealer today and dropping my hard-earned cash on quality Mopar parts. I bought them this morning(spent about $75), ripped the parts out of the bags, and popped my hood. It was at that point I realized that I suck at working on cars. I looked at my engine, then at the seemingly thousands of hoses in my hand, then at the engine again, then I figured that I'd might as well give the hoses in my hand another look. I saw nothing in my engine that looked like what I was holding. I temporarilly gave up and went ahead and finished my oil change.
I came inside and gave the above page a thorough reading. It seems that the article refers to the 87-90 4.0, whereas I have a 91. Crap. Well, that'll teach me to skim past the instructions. So now I need to know what to replace to get rid of blowby on my H.O. 4.0. I'm going to the dealer on Monday to get my refund, so I'll just get the parts I need while I'm there. I posted this at other forums and some people mentioned a kit that the dealer sells. Should I jsut ask for a blowby kit? Thanks in advance.

-Ed

When you go back on Monday just ask for the parts that fit you XJ. The main problem is the little tube gets plugged. I do not know the recommended interval for your XJ to change all those parts but mine is 50,000 miles.

I'd go ahead and change the little tube, sometimes called the PCV valve even though it is an orfice. Also check the fitting the little tube attaches to the intake manifold. Make sure you have vacuum there. If you have a vacuum gauge test to see how much vacuum.

I did change all those parts and still had a problem until i have my cat converter replaced. It was partially stopped up and making back pressure. If you get time this weekend take your rig to a muffler shop, pay them the 20-40 fee to test you cat and confirm it is good. My buddies and I have come to the conclusion replacing at cat at 100,000 miles is something everyone should be doing, they do get "used up".

I know replacing the cat is not on any web site but it what finally fixed my oil in the air box problem.

Follow the write-up in this article.

I have a '91 also and it has done wonders...

Don't let the title mis-lead you