• 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.

My engine pukes oil...help?

Muddy Beast

Muddy Beast

NAXJA Forum User
Location
WA
A little background, '89 Cherokee with 211k on it. Last oil change was probably 2k ago using 5w-30 and a fram filter (I know, I know). Well first, I replaced my oil pan seal, rear main, and head gasket seal a year ago...but my rig is now leaking about half a quart a week or two. It was sealing just fine...but a few months ago it started leaking more and more.

Second, I was on the freeway trying to keep up with my friend the other day and he called me telling me I was smoking like crazy (full throttle, probably happend at 70mph) so we pulled off at a truck stop. During the smoke I'd checked my gauges and all read normal, oil pressure was probably 3/4th to the top, 200temps. At the truck stop I had oil dropping everywhere and it seemed like it came out my dip stick (I constantly have to push it back in). But after driving it around for awhile later that night I had just a normal small oil leak (a few drops an hour).

What's the deal, is something clogged up? Should I drain the oil and replace the filter?

~Scott

P.S. After my little smoke thing, there was oil all over the hood right around the dip stick/filler area.
 
You are seeing the results of blowby. It pressurizes the crankcase. Ideally you have a ccv system that vents the valve cover into the intake to relieve the pressure. Over time it gets clogged. You can get a completely new one for around $25 if I remember right or you can pull yours off and flush it out yourself. The clog can also be inside the valve cover where the vent mounts. You have to pull the cover, remove a couple of screws on the baffle and then clean everything before reassembling. A search on blowby will yield a wealth of info on this.

By the way if you are puking oil out the dip stick, you may also have oil in the distributor. This can lead to a coating on the inside of the distributor cap causing a misfire.

While blowby isn't a terminal disease, it does cause a mess. And by the way, get rid of that FRAM.
 
So what hose am I looking for? The big rubber one at the top of the intake?

Reason I ask, I plugged all of those hoses off when I made a homebrew air intake...sounds like this could be the cause. The main front one on the valve cover I have a catch can and a breather vent at the end though...

~Scott
 
The big one lets air in that is in the middle of you valve cover. Toward the rear of your valve cover you will see a little tube that is plastic that routes its way toward the front of your intake manifold. this one suck air out of you vavle cover and is the one that gets clogged.
 
Ya I checked that one awhile ago and couldn't get any gunk out of it (put wire through it almost all the way)...is there a mod to fix it?

~Scott
 
Yes That is most definitely the cause, That hoses only purpose in life is to vent those blow by gasses in the crank case. It does the same job as a PCV system on other engines. So if you cap it off the gasses will find other ways out. whether it be the dip stick or by blowing out the weakest seal it can find. Sence you have made a custom intake the best thing you can do is probibly find one of those genaric little valve cover filters. You can find them at most auto parts stores.

Good luck
Andy
 
Another problem with the RENIX system is all the vacuum lines. Try pulling your oil fill cap off and replacing it with a filter cap. I had a problem years ago with a 88 XJ and when i did that, the pressure didnt build in the engine and it fixed my problem. If course the right thing to do is fid and fix the vacuum problem but thats easier said than done.
 
Muddy Beast said:
So what hose am I looking for? The big rubber one at the top of the intake?

Reason I ask, I plugged all of those hoses off when I made a homebrew air intake...sounds like this could be the cause. The main front one on the valve cover I have a catch can and a breather vent at the end though...

~Scott
Click to expand...

BINGO
 
Alright lets take a step back for a moment. The intake has 2 small hoses and one large rubber one, it also has a hose coming from the front of the valve cover. The one at the front of the valve cover I have a breather on. The hose at the back of the valve cover just goes through to the vacuum. The little hoses are plugged though.

Which ones am I looking for? Quick picture for reference?

~Scott
 
Unplug the small hose at the back of the valve cover, which goes to manifold vacumn. The valve cover has some flaps that are suppose to prevent vapors from coming out the front. If the back line is plugged, you can build a little crankcase pressure which will make it puke out all the other places, including the dipstick.
 
start over w/ NEW, vacuum lines, i bought mine from napa, theres 2 parts and its NICE having the new stuff...

breathers are just gonna make a mess, that oil isnt just gonna vaporize into thin air, it goes somewhere -- all over the top of your 4.0--
 
I'm thinking I am having the same problem with my '89. there is oil all over the top and passenger side of the motor. its not bad to the point of blowing my dipstick out but I do have oil in the air filter and when i rev it with the oil cap off its definitely blowing oil out. I bypassed that cheesy oil junction thing and routed all the hoses directly to their respective destinations and it seems to idle smoother. the one thing I haven't done is replace the hose between the airbox and the front of the valve cover which i should just take out because it is plugged and has zero flow through it.

with all that said would it still make sense that it is leaking oil similar to a rear main seal leak? I would love if it was the vacuum problem and still had some life in my rear main seal... I'm not looking forward to that job, especially if it doesn't fix the problem @_@
 
It amazes me how people screw with stuff they have no clue about, have problems because of it and then ask for help fixing it.............. If you are not sure about something ask someone who does or research it before messing with it........:doh:
 
ColoradoRaptor said:
It amazes me how people screw with stuff they have no clue about, have problems because of it and then ask for help fixing it.............. If you are not sure about something ask someone who does or research it before messing with it........:doh:
Click to expand...

Except everything done to my motor was done from this websites advice. My only line I changed that comes off the valve cover was the front one, and I did a breather with a catch can so the oil blow by does go everywhere. The rear hose I haven't changed. It was new a year ago, I also took a compressor and cleaned it...I think my problem lies else where. It seems pretty clean. I know my cruise control doesn't work which leads me to believe I have a vaccum leak, but when I unplug my bottle I get a bunch of air rushing...and from what I understand that means my vaccum should be fine.

What are other causes other then that one hose off the valve cover?

~Scott
 
when my brother inlaw owned my jeep, he bought all new blow-by hoses and a few vac hoses, dealer price was like $300 bucks..

one more reason i bought it.. haha i hate blow-by issues
 
Muddy Beast said:
I know my cruise control doesn't work which leads me to believe I have a vaccum leak,
~Scott
Click to expand...

Is your torque converter locking up? If not, then check the white switch on the brake pedal up near the top. That's the switch that tells the trans computer to unlock the t/c and the cruise to disengage. It can get dirty and stop working. I can be popped apart and cleaned
 
lawsoncl said:
Is your torque converter locking up? If not, then check the white switch on the brake pedal up near the top. That's the switch that tells the trans computer to unlock the t/c and the cruise to disengage. It can get dirty and stop working. I can be popped apart and cleaned
Click to expand...

Well I doubt I can get it to work now since I have a WJ booster (aka grinded brake lever) it stopped working prior to the swap...but I have a feeling it won't work now with the brake set up.

~Scott
 
Muddy Beast said:
Well I doubt I can get it to work now since I have a WJ booster (aka grinded brake lever) it stopped working prior to the swap...but I have a feeling it won't work now with the brake set up.

~Scott
Click to expand...

The switch I'm referring to is seperate from the brake light switch. This one is further up the pedal and also had a vacumn line attached to it. It's supposed to break the vacumn to the cruise control when you hit the pedal as well. It that's missing, not only will it not see the switch, but you might have a vac line hanging and preventing the cruise solenoid from working.

If you don't have that switch and you have an auto, I'm fix that as you're just adding heat to the tranny by not locking the t/c. I don't have that switch, but instead hooking up a relay to the brake light wire. The swtich is normally closed when the brakes are not applied.
 
Weird...that's a good point. I have a switch with two plugs coming off it, my understanding it the end is for the brake lights and the top is for the cruise control. I never once saw a vacuum line...maybe that's a big part of my problem?

~Scott
 
cruise_switch.jpg


Here's the switch I was referring to. Looking at it again, I think its just the vac break for the cruise and the switch for the tranny. I'm not sure if the cruise cancel is triggered by the regular brake switch.
 
You must log in or register to reply here.

Similar threads

B
Oil leak.
2
Replies
38
Views
6K
Bmfinney
B
A
1987 4.0 oil pressure problem
Replies
1
Views
1K
RCP Phx
R
B
Reasons for white exhaust smoke besides head gasket?
Replies
1
Views
819
RCP Phx
R
M
Oil pressure question
2
Replies
26
Views
3K
Money_Pit_Incoming
M
T
Oil In AIr Filter/Not Passing CA Smog
2
Replies
22
Views
4K
cruiser54
C
Back
Top