[jeepholic]

Does someone know what it means when your air filter gets oil on it, it is happening allot latley.
PS when that baby hit 200k miles problems started popping up like carzy, just did the CPS today and started doing a rear tranny seal...fun fun fun.

[Texas ZJ1]

Wow,

stumped me on this one. My air filter is always oily because of the filter element.

Hunter

[jeepholic]

Originally Posted by Texas ZJ1

Wow,

stumped me on this one. My air filter is always oily because of the filter element.

Hunter

Are you saying that the air filter in my 4.0 I6 is supposed to be soaked in oil, I have two vents on the top of my valve cover, one is in the back and the one near the front has a tube going to the air filter box so I assume oil can get over there, but it doesn't look like any air can get through it, because it drips oil, only the edges, the center of the square air filter is still dry.

[miataeric]

Originally Posted by jeepholic

Does someone know what it means when your air filter gets oil on it, it is happening allot latley.
PS when that baby hit 200k miles problems started popping up like carzy, just did the CPS today and started doing a rear tranny seal...fun fun fun.

Sounds like blow-by to me.
Google says: http://www.off-road.com/jeep/cherokee/xjtech/engine/40ltr/blowby.htm

[jeepholic]

That's it exactly thanks so much!!!!!!

[Texas ZJ1]

No, your's is supposed to be dry. I have the turbcity dual air intake. Mine is supposed to be dry hence me saying that you really stumped me on that one.

Hunter

[LBX2G]

I asked my high school mechinic teacher about this. He said it is cloged and to replace the ccv valves and not to worry about. and that is normal wear and tear. Nothing to pull ur hair out about.

[jeepzjlimited]

I've had this problem as well on my '94 4.0 I6. It seems under acceleration the front CCV on the valve cover can "spit" oil from the crankcase out onto the air filter. To remedy this problem I have simply removed the hose that goes from the front valve cover CCV to the factory airbox. Placed a breather filter on the front valve cover CCV nozzle and blocked off the airbox nozzle.

No problems or oily air filter in months now .

[greasefingers]

This issue should really be a “sticky” It has been written up several times in great detail. I will tell you what I know: the rear plastic line is connected to the intake manifold. The manafold pulls a slight vacuum on the valve cover and recycles the blow-by gases back into the combustion chambers. The front line is connected to the air filter. From this line, it purges the blow-by gases with fresh air. If the rear line is disconnected or block/clogged, then you do not have a purge in your valve cover anymore. If blocked then the valve cover becomes slightly pressurized, so the oily vapors are force in the reverse direction to the air filter and deposit on the top of the filter. Remove the rear line and clean it with brake fluid. If this CCV line is disconnected, then you may smell and see the vapors.

The two elbows at each end of the 4.0 liter engine are different. The one at the front is a normal elbow(Mopar pn# 53030497 $4.60) This allows a fresh air purge of the vapors inside the valve cover. The rear one is called the vent or CCV valve (Mopar pn# 53030495 $6.10). Gases flow out of this and into the Intake manifold. One end of the CCV vent, the part inside the valve cover, has a metered orifice in it about 1/8” OD. This meters the amount of blow-by gases introduced into the intake manifold. You will also need two rubber gromets for the valve cover (Mopar pn# 2946079 $ 4.35/ea)

[slaterny]

I love this jeepforum, but I have an issue with this particular thread. It sounded like what was described here is exactly what was happening to my zj. I clicked on the link that has a detailed description along with specific mopar part numbers for a fix. I went to the dealer and got the exact part, but it didn't fit! It turns out that the link with the part numbers was for xj's not zj's!

Looking at it after the fact, I see that now, but when you are trying to diagnose and fix a problem, I guess you assume that any information under the "Grand Cherokee" forum would be related to just that.

That's my .02

[jeepholic]

The link was directly to an XJtech page, even has a pic of an XJ, and while the problem is the same the part #'s may be different.
About the problem, once I cleaned my vents and made sure I had good vacum in the back vent the problem went away. The valve cover makes a vacum inside, and with out it you will get oil on the air filter.

[Meerkat]

Originally Posted by greasefingers

This issue should really be a “sticky” It has been written up several times in great detail. I will tell you what I know: the rear plastic line in connected to the intake manifold. It pulls a vacuum on the valve cover and recycles the blow-by gases back into the combustion chambers. The front line is connected to the air filter. It purges the blow-by gases with fresh air. Your rear line is disconnected or block/clogged. So you do not have a vacuum in your valve cover; anymore. The valve cover is now pressurized, so the oily vapors enter the air filter and deposit on the top. Remove the rear line and clean it with petrol.

Ask, and ye shall receive....
FAQ entry

[NowBetter]

Originally Posted by slaterny

I love this jeepforum, but I have an issue with this particular thread. It sounded like what was described here is exactly what was happening to my zj. I clicked on the link that has a detailed description along with specific mopar part numbers for a fix. I went to the dealer and got the exact part, but it didn't fit! It turns out that the link with the part numbers was for xj's not zj's!

Looking at it after the fact, I see that now, but when you are trying to diagnose and fix a problem, I guess you assume that any information under the "Grand Cherokee" forum would be related to just that.

That's my .02

Hi...

On the bottom of that detailed description of how to deal with the problem it said that it was for Cherokee/Comanche Jeeps only... But I guess it is "misleading" in a way if you don't read the whole article.

Have a good one guys...

[Dr. Righteous]

FIRST OFF.
In a CCV (Constant Crankcase Ventlation) there is no one way valve like in a PCV (Positive crankcase ventlation) on a V8. The 2 plastic fittings on top of the valve covers are elbows only. What limits the airflow is the oriface size (brass fitting). The purpose isn't to pull a vacuum in the crankcase but to maintain a slight low pressure so blowby gasses will not cause performance problems with the engine. It all works good but usually gets 0% maintenance, so by the time the adverage Jeeper gets it the system isn't working correctly.

When I bought my '94 ZJ 4.0L, it had an oil smell while driving.
When I check under the hood I noticed a oily vapor coming out around the CCV gromets on the valve cover. Closer investigation showed that all parts of the CCV system was pretty much shot. The brass oriface that screws into the intake was totally clogged so it couldn't have worked anyway.
Went to the Jeep dealer parts counter and discussed the problem. It turns out it is very common on Jeeps with the 4.0L and they knew all the part numbers by heart when I told them the year. The breather tube was out of stock but they pulled one or a XJ and said to turn it around backwards and it would work. The bends in the plastic tube are in different places for a XJ. Everything was less than $50 and I installed the parts and had a working CCV system.

[GettinStuck]

i worship this thread... i thought i was screwed. my local mechanic told me i was going to need an engine rebuild.