misch

Hello,
I have recently purchased a 1990 XJ (4.0l auto), I previously owned a 1998 and had never heard of the Renix engines so I am learning quite a lot. When I bought this one, the owner pointed out the two oil catch cans and said they needed to be emptied every 200 miles or so (I now know that is not good!). I am looking into solving this issue, but I can't find a single mention of anyone having TWO catch-cans installed or how to delete them. Here are my concerns:
-The rear can is connected to the rear opening on the valve cover, where the CCV valve should be, then outputs to the intake manifold. The hose from the valve cover is attached to some sort of filter I think, which is just loosely sitting in a grommet? So it's not held in by anything, and oil definitely gets out through there and coats my valve cover. I would like to replace this with the stock CCV valve and tube.
-The front can is directly hooked up to the front opening on the valve cover, where the vacuum harness should be attached, and then outputs above the air filter. The air box has been deleted, I just have one of those cone-shaped filters. This catch can fills up a lot quicker than the rear one, like I do need to check it every 200 miles.
-I've been looking at replacing the vacuum harnesses (front and rear, from the Dorman Help brand) but since most of it seems to be missing from my Jeep, how could I go about this? I don't have the ports that would have been on the air box, and I can't see where the rest would be connected since it's been mostly removed.
-I am planning on doing Cruiser's valve cover mod, I'm also making my way through the other tips.
-I've just realised my head gasket is bad, so I am replacing that, which I'm hoping will reduce most of the blow-by (it is a lot of water in the cans, not just oil). I am researching more about the blow-by issue and would really like to not need the catch cans.

I hope my descriptions are clear enough, I love this jeep and really want to fix her up to last for a while! Currently sitting just under 150k, so she's got a lot of life left in her I hope.

Thanks in advance for any help! I can answer questions and post pictures if needed!

*EDIT*
Since I am doing my head gasket, I will have the head off and will investigate and clean it up and try to fix any issues with the head and block. I am mostly wondering about how to deal with the catch cans and vacuum harnesses once that is all done. Thank you

agreen

Every 200 miles!?!

Ok so that's a lot of blowby. Replacing the head gasket won't fix the blowby issue. Your engine was probably abused. You might try some Berryman Chemtool or Seafoam in the cylinders overnight to help unstick the rings, but I don't have high hopes for that. It might be worth a shot, but you're probably going to have to rebuild the engine.

Right now, the catch can(s) are helping keep the oil off the throttle body. If it fills up the can(s) in 200 miles, you might want to keep them for now.

xxEuroBabexx

Hooooly-- Please post pictures that sounds terrible. You should 100% pull the head . If you can't do the major fixes now then you might wana just keep those catch cans.

ELC_AMX

Yeah that might be a dying engine. Unless you like oil all over everything then I'd probably just keep the catch cans like EuroBabe said, and start doing some deeper diagnostics on the engine. For starters you should be able to feel a LOT of blowby if you pull the oil fill cap while the engine is running, just hold your hand over the opening.

The blown head gasket could potentially cause some of this issue, though what percentage depends on how abused the motor was, how worn out it is now, and where the head gasket is leaking. I'd say that you should start to tackle the head gasket sooner rather than later, because what you find by pulling the head could tell you a lot. Either you find nothing wrong internally and the new gasket helps solve the excess crankcase pressure causing oil to leave in such high amounts, or you find that you definitely need a rebuild and instead of finishing up the gasket job you pull the motor and have everything that needs done, done.

Edit: The catch can deletes are pretty simple once you don't need them anymore. XJ CCV/PCV (I forget which type it is) routing is very easy and can be done entirely with off-the-shelf parts from an auto parts store, no OEM equipment needed.

cruiser54

If the system were returned to stock, and one mod done, it might be just fine.
A dry then wet compression test should be done first.
Following links give all you need.

http://cruiser54.com/?p=131

http://cruiser54.com/?p=121