Keithmania
NAXJA Forum User
- Location
- Zanesville, OH USA
This is kinda long, but I think the info is worth the read...
I have a 1990 Renix rig that has had some on again off again issues lately and I wanted to pass along what I have found. I was unlucky enough to find out that this XJ had the vacuum shift actuator on the front axle. I found this when my transfer case bit the dust and instead of replacing it with the transfer case that had the vacuum solenoid on it, I just swapped in a regular NP231. The boot for the vacuum hoses to the axle disconnect was fubar'd so I decided to ditch that too and install a manual cable disconnect.
I had at one point also cracked the CCV/vacuum assembly and didn't think anything about it til I decided to move to Ohio. On the drive here, wow, did it start to leak like a sieve. I thought the rear main seal had gone on it, wasn't looking forward to the replacing it, and didn't for a second associate the leak with the CCV.
Before doing anything else, I had noticed some emulsified oil when I finally got into Ohio and decided it needed a head gasket replacement. While I had things apart I installed a '93 HO-0630 head cause I was tired of how gutless it felt. So I get everything back together and it cranks over almost immediately. Took it for a quick spin around the block and the seat of the pants feel felt much better in the seat of my pants! I run it for a bit and recheck fluid levels, check for oil leaks and everything seems bueno. The Jeep gods decided that my work was subpar and smote my jeep.
After about a week it had emulsified oil again, and was leaking as bad as it was before. Didn't figure the oil leak would go away but I definitely thought I took care of whatever was causing water to get into the oil... So, I go into troubleshooting mode and I get stumped...
Since at this point I am avoiding the rear main seal replacement I decided to go ahead and replace the CCV/vacuum assembly. That had an immediate effect. I noticed a slightly smoother idle, and to my surprise the oil leak from the rear main disappeared! What the heck? The only thing I can guess is that the amount of crank case pressure has drastically decreased and has allowed the rear main to reseal. Regardless, its still on my to fix list...
So, I still have this emulsified oil issue. Coolant levels are constant, and I mean, let-the-jeep-idle-in-my-drive-way-for-2-hours-with-no-change-in-coolant-level-after-it-was-warm-constant... The amount of the emulsified oil was minimal, but I couldn't leave anything to chance. So I go over every last vacuum hose in the engine bay and lo and behold, remember that axle disconnect hose assembly that I mention above? Yeah, I had missed plugging a line and it was suckin' air directly beneath the coolant reservoir. It also happens that the emulsified oil appeared right after I topped off the coolant reservoir and accidentally let it over flow. So I plug the offending vacuum hose, idle drops about 100 rpms and let it idle for another 2 hours. The heat dried out the emulsified oil at the bottom of the oil pan and it still doesn't leak.
Hope this info helps someone, I never knew how important the Renix CCV system is, don't hesitate to replace it when it starts to get old and brittle and watch that vacuum assembly below the coolant reservoir, at the very least check it out if you have one, on a rainy day if it leaks it would be an easy way to get some moisture in your engine...
I have a 1990 Renix rig that has had some on again off again issues lately and I wanted to pass along what I have found. I was unlucky enough to find out that this XJ had the vacuum shift actuator on the front axle. I found this when my transfer case bit the dust and instead of replacing it with the transfer case that had the vacuum solenoid on it, I just swapped in a regular NP231. The boot for the vacuum hoses to the axle disconnect was fubar'd so I decided to ditch that too and install a manual cable disconnect.
I had at one point also cracked the CCV/vacuum assembly and didn't think anything about it til I decided to move to Ohio. On the drive here, wow, did it start to leak like a sieve. I thought the rear main seal had gone on it, wasn't looking forward to the replacing it, and didn't for a second associate the leak with the CCV.
Before doing anything else, I had noticed some emulsified oil when I finally got into Ohio and decided it needed a head gasket replacement. While I had things apart I installed a '93 HO-0630 head cause I was tired of how gutless it felt. So I get everything back together and it cranks over almost immediately. Took it for a quick spin around the block and the seat of the pants feel felt much better in the seat of my pants! I run it for a bit and recheck fluid levels, check for oil leaks and everything seems bueno. The Jeep gods decided that my work was subpar and smote my jeep.
After about a week it had emulsified oil again, and was leaking as bad as it was before. Didn't figure the oil leak would go away but I definitely thought I took care of whatever was causing water to get into the oil... So, I go into troubleshooting mode and I get stumped...
Since at this point I am avoiding the rear main seal replacement I decided to go ahead and replace the CCV/vacuum assembly. That had an immediate effect. I noticed a slightly smoother idle, and to my surprise the oil leak from the rear main disappeared! What the heck? The only thing I can guess is that the amount of crank case pressure has drastically decreased and has allowed the rear main to reseal. Regardless, its still on my to fix list...
So, I still have this emulsified oil issue. Coolant levels are constant, and I mean, let-the-jeep-idle-in-my-drive-way-for-2-hours-with-no-change-in-coolant-level-after-it-was-warm-constant... The amount of the emulsified oil was minimal, but I couldn't leave anything to chance. So I go over every last vacuum hose in the engine bay and lo and behold, remember that axle disconnect hose assembly that I mention above? Yeah, I had missed plugging a line and it was suckin' air directly beneath the coolant reservoir. It also happens that the emulsified oil appeared right after I topped off the coolant reservoir and accidentally let it over flow. So I plug the offending vacuum hose, idle drops about 100 rpms and let it idle for another 2 hours. The heat dried out the emulsified oil at the bottom of the oil pan and it still doesn't leak.
Hope this info helps someone, I never knew how important the Renix CCV system is, don't hesitate to replace it when it starts to get old and brittle and watch that vacuum assembly below the coolant reservoir, at the very least check it out if you have one, on a rainy day if it leaks it would be an easy way to get some moisture in your engine...
