comanche leak/missing cover?

[waffleman]

Hello, so I just today purchased a 4.0 automatic comanche, I have next to no experience with them and I don't pretend to be an expert when it comes to vehicles but I feel I have a reasonable know how when it comes to general maintenance 
When I got home I noticed that it was immediately dripping, I look under the truck and and notice there is a lot of fresh oil and what appears to be a missing cover of some kind. Again, I'm no expert...but my guess is it should NOT look like that. The guy told me it had been sitting for awhile and I noticed oil accumulated on the pan but figured it was leaking from somewhere else.
Can someone tell me what i'm looking at, and what I need, i tried searching through some google images and couldn't find anything that makes sense of what i'm seeing here.
Thank you much, hopefully I don't have to return the truck with the threat of legal action against the guy I bought it from.

[kryptronic]

You're missing the bottom half of the inspection cover for your transmission.  That is not good and you need to get one, but that's not causing your oil leak.  It just exposes your transmission to unwanted dirt and grime.  Trace the oil to deternine the source of the leak.

[Keyav8r]

The leak could be the rear main seal.  But, it could also be the valve cover.  Or the distributor o-ring/gasket.  Or the oil filter housing o-rings.  Or ...........

All engine oil leaks have a tendency to run to the back of the engine and the oil pan is the low point where they end up.

You’ll just have to eliminate the possibilities one at a time.  Start at the top (valve cover) and work your way down and back.

[DirtyComanche]

Hose the whole thing down with brake clean and then try to find where it's leaking from.  I'd start with it being the back of the valve cover though.

 

You can get away with running without that inspection cover on the street in the summer...  I'd have it on for everything else.  Easy part to get from the junkyard.  Snag the bolts for it while you're at it.  Edit - the Cherokee one is the same if you're not aware.  Lots of Cherokees in the junkyard, normally.

[rokinn]

The leak could be...all of the above.  Was for me!  I saved the rear main for last because it's time consuming cleaning off the mating surfaces if it's never been done before.

[Keyav8r]

And, it’s a pain in the @$$ to get the oil pan off, especially on a 4WD.  If you go that far, replace the oil pump while you’re in there.  Might even consider replacing the main and rod bearings.  A little more time and a few more bucks.  It’s a J(ust) E(mpty) E(very) P(ocket), after all.

[RustyRodder]

2 hours ago, Keyav8r said:

And, it’s a pain in the @$$ to get the oil pan off, especially on a 4WD.  If you go that far, replace the oil pump while you’re in there.  Might even consider replacing the main and rod bearings.  A little more time and a few more bucks.  It’s a J(ust) E(mpty) E(very) P(ocket), after all.

\Yup, mine needs it done.  We're just pulling the engine to do all that.  might dingleball the cylinders, do the rings and lifters while in there. 

[kryptronic]

Don't freak out, waffleman.  These guys are discussing the rabbit hole that is Jeep ownership.  We've all got the opinion we might as well fix, modify or enhance everything we see once we crack something open.

 

To get your leak fixed, you could replace every gasket on that engine for under $100 in an afternoon with a jack, jackstands and common tools, like a socket set and torque wrench.  The same job at a shop will run in the $400-600 range.  Follow other threads on here for tracking down your leak, and fix it properly.  You'll need a new gasket, or three.  The most important thing is to ensure you properly torque all bolts.  They don't go on as tight as you'd think they would.

[cody4359]

I've been missing that cover for nearly 6 years, it's not a dd but I goes in the mud and snow. Finally got a cover about 3 mo that ago and still haven't out it on. rear main seals are a bit of a pain, the worst part is getting the oil pan out from under a near stock height rig. remove starter, track bar, drag link and disconnect yhe sway bar then jack as high as you can go

Sent from my SM-G900V using Tapatalk

[cruiser54]

I’d be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

Everybody, who doesn’t own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. Many mechanics, friends, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?

A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don’t jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons:

First off, the engine sits nose-up and any oil will run back to the RMS area.

Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber’s adage apply here: “Crap flows downhill”.

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.

[87MJTIM]

The OP has not replied to all our posts.  He also posted the same question on JeepForum and has not replied on there.  

[waffleman]

Hey sorry, I locked myself out of my account and had work.

I'm thinking about just snipping some galvanized flashing to size and putting it over the cover area just to keep it clean. It might be ok as is but I don't want to risk it. 

 

As for the leak I'm hoping to have a day here in Washington without rain so I can give it a look. 

There's a few vacuum hosed and some of the metal pipes under the hood look rusted so I'll be making a few trips to my local junkyard hopefully soon.

Thanks for all the input and info guys

[Kyleinreallife]

I’d be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

Everybody, who doesn’t own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. Many mechanics, friends, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?

A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don’t jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons:

First off, the engine sits nose-up and any oil will run back to the RMS area.

Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber’s adage apply here: “Crap flows downhill”.

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.

And at the very tippy top, your oil cap, the bushing gets worn out over time and oil can dribble out.


87' 4x4 Sportruck

[cruiser54]

DIAGNOSE the leak. Could be as simple as loose valve cover bolts.

 

For the vacuum harnesses and routing: