• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

oil in the the air box

I had the same problem - replaced the CCV assembly (the smaller tube on the back of the valve cover) and haven't seen any oil in the filter yet. I also have an '87 and I have 230K miles on it. It's an easy fix and well worth attempting before replacing everything.

Actually just went out and checked the filter again to make sure all is still well and it is. I've put about 200 miles on it since the filter swap. Not sure if that's long enough to know for sure, but the air filter looks brand new.
 
Last edited:
OK let's try this ONE more time....what in the pic below shows any sort of fix for oil blowby? Like pulling damn teeth around here jeesh

mcnamaag said:
Try this for a cheap and easy fix. I did mine about 500 miles ago and havent had the problem since. Plus its a lot cheaper and easier to clean out than the plastic lines.
IMG_0047.jpg
Click to expand...
 
to me it looks as though he increased the Id of both parts, the 5/8" to the airbox and the alum tubing which has a large ID than the stock plastic tub
 
kd5dwy said:
I had the same problem - replaced the CCV assembly (the smaller tube on the back of the valve cover) and haven't seen any oil in the filter yet. I also have an '87 and I have 230K miles on it. It's an easy fix and well worth attempting before replacing everything.

Actually just went out and checked the filter again to make sure all is still well and it is. I've put about 200 miles on it since the filter swap. Not sure if that's long enough to know for sure, but the air filter looks brand new.
Click to expand...

how did you get a new CCV asembly? did you have to go through a dealership?
 
I bought mine through the dealership. It's called a CCV kit. I'll try to get the P/N for you. I've also heard you can get the part through NAPA.
 
UncleBud said:
I still don't get how blue hose instead of black stops the oil blowby can somebody elaborate please?
Click to expand...

The small CCV hose draws air from the valve cover into the air intake manifold. The larger hose supplies fresh air to the valve cover (crankcase, hence the term crank case ventilation, CCV). The blow by gases flow (under normal circumstaces) into the small tubing mixed with some fresh air (normally). When the small tube gets clogged (which happens easily) the air, and oil mist in the crankcase (blowby) accumulates and flows backwards into the air filter since the air filter box is under a vacuum.

There is nothing special about the hose(s) or sizes. The only critical part(s) seems to be the yellow/tan fitting with a precise orifice in it in the end of the small tube as it attaches to the valve covers rubber bushing.

I have removed the orifice in mine and increased the CCV flow rate as of 6 weeks ago, as well as cleaned and replaced some of the larger tubing with hose. The hose is just easier for many of us to get, and far less fragile than the OEM tubing. I also replaced pieces of the small tube with rubber vacuum line hose as it broke in several places while trying to clean it. The small OEM tubing that I reused has become the orifice on mine!

Removing the CCV orifice in mine has not affected engine performance as far as I can tell, at least not in mine. It already sucked :(, :laugh3: and not in a good way.

But it might act like a small vacuum leak in others! Not sure, just a topic I am still investigating. May be that the Renix ECU and IAC have simply compensated for any extra flow in mine (becuase I removed the orifice) making it transparent.

Also, for those with worn rings and excess blowby, eliminating the orifice may be part of the solution to oil in the air filter!
 
UncleBud said:
OK let's try this ONE more time....what in the pic below shows any sort of fix for oil blowby? Like pulling damn teeth around here jeesh
Click to expand...

By the way, didn't you read the FAQ on tooth extractor requirements here! :eek: LOL.

Anyway, Sorry it took so long for you to get a precise answer to your question (I think I just answered it, at least I tried).

It takes a while, but if you take the time and read and search the threads here you will eventually find the answer(s) to many of your questions already here, somewhere, sometimes not always in an obvious thread.

I have been looking for certain Jeep answers for 3 + years, and I have learned more in 8 weeks here than I learned in 3 years at other sites.
 
I realize that the cool blue hoses won't fix the problem. When I hop up on the Interstate and run for a few hours (200 miles) I blow a quart of oil out on the engine and then it's smoking and stinking. I'm looking for a way to prevent that.

I will try and replace the CCV kit and see if that helps solve the problem, but I also was asking for other workarounds short of an engine rebuild.

Thanks !
 
AlabamaDan said:
I realize that the cool blue hoses won't fix the problem. When I hop up on the Interstate and run for a few hours (200 miles) I blow a quart of oil out on the engine and then it's smoking and stinking. I'm looking for a way to prevent that.

I will try and replace the CCV kit and see if that helps solve the problem, but I also was asking for other workarounds short of an engine rebuild.

Thanks !
Click to expand...

Sounds like serious blow by, worn cylinders, piston rings, or valves....?

What other problems are you having. Oil in the exhaust? Oil on spark plugs? Blocked exhaust?

Have you tried higher viscosity oils, like Lucas or 20W 50?
 
AlabamaDan said:
Thanks guys.



So if I just route the hose to the ground and have it end below the engine so it doesn't spew oil on my motor (causing that buring oil smell) will that keep the airflow imbalanced? Does that cool blue hose still go to the airbox in the photo?



Surprisingly I don't think I have a leaking valve cover, but I'm blowing alot of oil through that hose.



Oh, we need signatures. I have an 88 XJ, I6, AW2, 231 TC. (I think that's the number of the TC.)
Click to expand...
First mine spewed oil about a quart in 150 miles or more. I think the valve cover seal is the main culprit. I also did the MAD-XJ big tube conversion. You have to cut apart the 99+ CCV tube into section and then use fuel hose attached to them. You could use a valve cover breather as the Ricers do. I'd get one with a shield at the front, so your engine isn't sucking in dirt. The front tube goes to the airbox for filter air. If you don't have a filter on it, then you will probably suck in some dirt. Not good for your engine. I'd also try sticking the end of a paper clip or a small drill up the end of the rear tube. This might clear out the blockage.
Tom
 
Ok. I'm blowing about a quart out every 200 miles. I don't think it's the engine per se' as it wasn't doing this when I bought it a month ago. The guy I bought it from just used it to putter around time. I drove it around town and it did fine for about a week or so, then Thanksgiving I put it on the interstate and it started during that trip.

I haven't had a chance to work on it since my last post. I've been covered up with hunting season and just keep checking (read that adding) oil frequently.

Hopefully this weekend will allow some time.

I don't think that MAD-XJ conversion will work for me since I've got an 88.

From what I've been reading the hose at the front of the valve cover isn't really a problem, it's the CCV and the hose from it to the manifold. I'll try and replace those this weekend and see what happens.

Hard to tell now, but I don't think there are any leaks around the valve cover.
 
AlabamaDan said:
Ok. I'm blowing about a quart out every 200 miles. I don't think it's the engine per se' as it wasn't doing this when I bought it a month ago. The guy I bought it from just used it to putter around time. I drove it around town and it did fine for about a week or so, then Thanksgiving I put it on the interstate and it started during that trip.

I haven't had a chance to work on it since my last post. I've been covered up with hunting season and just keep checking (read that adding) oil frequently.

Hopefully this weekend will allow some time.

I don't think that MAD-XJ conversion will work for me since I've got an 88.

From what I've been reading the hose at the front of the valve cover isn't really a problem, it's the CCV and the hose from it to the manifold. I'll try and replace those this weekend and see what happens.

Hard to tell now, but I don't think there are any leaks around the valve cover.
Click to expand...

main seal?
 
Does anyone know where I can get a PCV valve for my 94 4.0? Autozone and Kragen both don't list the part.
 
a quart of oil every 200mi is ALOT of oil to be losing. Even though it seems like it's coming from the front of the valve cover, I'd be willing to place a bet that your losing alot of that oil from a leaky rear main seal..or worse case scenario your rings are worn or you have a bad cylinder or something.
Have you actually checked the rear main seal? Sometimes when your at idle you won't lose much oil because there isn't much pressure pushing it out, but when you get on the freeway and your pushing higher RPM's and higher oil pressure it'll really flow outta there.
Definately fix the breather hose, but don't rule out the rear main seal either.
 
You must log in or register to reply here.

Similar threads

T
Oil In AIr Filter/Not Passing CA Smog
2
Replies
22
Views
4K
cruiser54
C
M
1992 XJ A/C Air Conditioning Replacement - Parts List
Replies
7
Views
2K
Rob Mayercik
R
M
The Infamous Oil Filter Adapter
2 3
Replies
46
Views
8K
Bent
Bent
M
Oil pressure question
2
Replies
26
Views
3K
Money_Pit_Incoming
M
Anak
How to Slot the CPS
Replies
4
Views
185
Evan03
E
Back
Top