Oil Problems with the 4.0

I've got a weird problem,
I have a 98 XJ 4.0 Auto, i drive every day 15 miles each way back and forth to work, it works flawlessly on a daily basis. The weird thing is that when i take it on a trip like today heading 90 miles to the Colorado Chapter Quarterly Meeting in Colorado Spings, i had problems on my way down. The drive is a tough drive on the XJ. My engine is running at 2800 to 4000 Rpm trying to stay up with the 75 mph speed limit which in reality is 80 to 85 on I-25 south. The tranny is cycling in and out of overdrive trying to haul my 35" MTRs, and pushing the 4.56 gears. My problem is that under this load the XJ starts to smoke out the rear, i pull over and and take a look. The inspection cover is leaking very badly about 3 to 4 ounces of oil drains out. This has happened to me 4 months ago and I replaced the Rear Main Seal and Oil Pan Gasket and it has worked well for the last 4 months. One thing i never understood is that the Oil Level in the motor increased the last time it happened . Again today i check my oil level expecting it to be low from the leak oil on the ground and all over the XJ and it's about a quart high and very thin. This is very strage because i just changed the oil 2 weeks ago and only put in 4 3/4 quarts. I know for a fact that the extra oil is comming from somewhere, but not sure where. It doesn't look like Anti Freeze, but could be Gas? I'm really Baffled.
Can anyone help me with this
John

Cruzzin_XJ said:

The inspection cover is leaking very badly about 3 to 4 ounces of oil drains out.

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Inspection cover? Which part are you referring to?

In regards to the oil, does it smell like gasoline? Cause you should be able to smell it if that was it.
Is your AntiFreeze low? Try looking a what is running low as that might give you a clue where it's coming from.

Also when you're looking at the oil does it seem homogenous or do you see a separation of sorts?

Also check the oil filler cap. Is there white scum on it? That's a sign of water in the oil. I wonder, too, if your crankcase ventilation system is clogged, and you're getting pressure in the crankcase. Make sure blowby isn't going backwards through the air intake (big hose at front of valve cover) and into the air cleaner, and check the little tube that runs from the rear of the valve cover to the manifold, and make sure it's clear. Oily gunk can clog it. That wouldn't explain the apparent increase in oil, but it might push oil out the seals when you run hard. It's hard to imagine how that much gas could get in from a fuel injected engine without a noticeable effect on driveability and economy. Back in the old days, a ruptured mechanical fuel pump diaphragm would do this, but there is no such beast on your 4.0. Very strange. The only other thing I can think of, related to general engine sludginess that might accompany a badly clogged vent system, is that if you checked the oil shortly after running, and there was accumulated oil in the head, you might have overfilled it. This might show up later when the oil is thinner and runs down more quickly.

Kejtar said:

Inspection cover? Which part are you referring to?

In regards to the oil, does it smell like gasoline? Cause you should be able to smell it if that was it.
Is your AntiFreeze low? Try looking a what is running low as that might give you a clue where it's coming from.

Also when you're looking at the oil does it seem homogenous or do you see a separation of sorts?

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Doesn't smell like fuel, Antifreee is fine, Haven't notice anything that is low. I'll look again tomorrow to double check everything
The cover that mounts to the bell housing and covers the Torque converter or Flywheel.

Thanks Remi
JOhn

Matthew Currie said:

Also check the oil filler cap. Is there white scum on it? That's a sign of water in the oil. I wonder, too, if your crankcase ventilation system is clogged, and you're getting pressure in the crankcase. Make sure blowby isn't going backwards through the air intake (big hose at front of valve cover) and into the air cleaner, and check the little tube that runs from the rear of the valve cover to the manifold, and make sure it's clear. Oily gunk can clog it. That wouldn't explain the apparent increase in oil, but it might push oil out the seals when you run hard. It's hard to imagine how that much gas could get in from a fuel injected engine without a noticeable effect on driveability and economy. Back in the old days, a ruptured mechanical fuel pump diaphragm would do this, but there is no such beast on your 4.0. Very strange. The only other thing I can think of, related to general engine sludginess that might accompany a badly clogged vent system, is that if you checked the oil shortly after running, and there was accumulated oil in the head, you might have overfilled it. This might show up later when the oil is thinner and runs down more quickly.

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I'll have to check the Crank Case breather and ventilation system tomorrow
4 monhs ago I thought i over filled it , so i draind the oil, let it drain over night and filled it a second time the next day, again after a long haul i had the same problem. I've been looking at it on a weekly basis and no noticible difference until today?
Any other idaes
Thanks again for the help
John

I had the same problem with my 4.0 when it was almost stock still. It turned out that it wasn't the engine at all. It was the transmission! The last time it was filled- before I got it- they didn't know how to check it correctly and it was overfilled. At speed with a large load on it, it pressurized and forced out tranny fluid. On mine it got on the exhuast and burned causing the white smoke.

Mine was an auto as well....forgot to say that!

When you look at the fluid was it redish, mine is dark brown, ??
I still don't know why my oil level is increasing, Theres no sign of foamyness, breaddown etc. I'm lost on this one. Maybe i can sell a quart at a time and get rich LOL
John

you could always send out a sample of your oil to be analyzed if youre really concerned and cant find the problem.

My tranny fluid was coming out dark brown. I have no clue what's up with the oil though.....
Wait, is your XJ named Valdez?

Glad to see mine isn't the only smoking XJ :laugh3: Mine is the rear main dripping on the exhaust pipe. Like the guys said, if it isn't milky or foamy, about the only thing could be is dilution with gas. You don't always smell it at first. A good thing to do would be to take a sample of your oil and have it analyzed. That is how truckers monitor the engine health. Most good truck repair places can tell you where to get it done.

You crankcase vent system depends on a vacuum to do it's job. Under the load you mentioned, your vacuum is about 0, so the blowby pressure will fiind the easiest path go escape, pushing some oil with it. This is usually the rear main seal, the oil filter adapter and the vallve cover gasket or top grommets and cap. The oil from most of these can end up dripping at the rear inspection cover as you described it. You'll probably find that your rig leaks far less after driving under light throttle conditions that it does when stressed by high speed runs, hills or heavy load such as towing a trailer.

I would bet the fluctuation in oil level is a separate issue that warrants further experimentation.

MaXJohnson said:

You crankcase vent system depends on a vacuum to do it's job. Under the load you mentioned, your vacuum is about 0, so the blowby pressure will fiind the easiest path go escape, pushing some oil with it. This is usually the rear main seal, the oil filter adapter and the vallve cover gasket or top grommets and cap. The oil from most of these can end up dripping at the rear inspection cover as you described it. You'll probably find that your rig leaks far less after driving under light throttle conditions that it does when stressed by high speed runs, hills or heavy load such as towing a trailer.

I would bet the fluctuation in oil level is a separate issue that warrants further experimentation.

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Now this is making since, Why wheeling Holy Cross i knocked off my Vacumn Canster, and have not installed a new one, i would bet i have less vacumn than normal and this would make it more sensitve. Another note, this morning while trying to figure out whats going on, i had no drips, no oil at all, Thats after i drove it home 50 miles and parked it over night. I did dirve on the slower side trying not to push it, My oil level seems to befineas well.

I think i need better drugs or something, this is to weird

Max, All, Thanks for the Input

Cruzzin_XJ said:

I think i need better drugs or something, this is to weird

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You’re getting old and need glasses. :woohoo:

Is that why my hair is turning gray?

if it taste sweet it's antifreeze...LOL mmm gotta love that flavor

If you're gonna bring back a thread with a quip, at least pick a good thread.