Slackdaddy

I believe I solved the weeping valve cover gasket.
But I still have a leak at the rear of the engine.
I am getting oil between the block and the sheet metal Spacer between the engine and the trans.
I am getting it on both sides, at the very outer "wings" of the block.
I am getting NO oil drips from the pan hump under the rear main, or on the crank hub.
I ran it for 20 minutes after repairing adjusting the valve cover gasket,, and even when the valve cover was leaking at the rear I had a rag back there on top of the bell housing, so I don't believe what I am seeing below is oil from when the valve cover was leaking.

Kinda stumped on what it could be,, Can freeze plug or oil galley plug weeping??
I checked the pan, it is all snug.

Drivers side


Driver side


Passenger side



Crank appears dry



I am at a loss,,
Last thing I want to do is pull the trans back out

cruiser54

There's a cam plug and a threaded oil galley plug.

Slackdaddy

I was thinking about them,,but the majority of the oil is on the drivers side, looking at the picture I attached (not my engine), it would be hard for the oil to make it from the cam plug and oil galley plug over to the drivers side?
There is no oil on top side of these "wings" of the block, just a mere 1-2" above???
I may pick up some UV dye and a UV light tonight.

I would think if the rear main was leaking it would have oil on the crank hub, or dripping directly below the crank from the pan ??

Slackdaddy

Well,
I put UV dye in the oil and ran it at 2000 RPM for 20 minutes, then let it sit for 10 minutes.
I have oil with the dye at the same places:
bottom of the block on each side, between the block and sheet metal spacer between the trans and block,
From there it is dripping down various places.
There is nothing showing up on the back of the valve cover, head or on the top the the "wings" of the block.
The flex plate and crank hub are dry with ZERO oil/dye.

So the oil is originating some where on the back of the block, between the block and sheet metal spacer.
If the oil galley plug or cam plug was leaking, I don't see how it would make it over to the driver side (They are on the far passenger side)
Is it possible for the rear main to leak and NOT have Any oil on the crank hub??

The joy is gone from this project

Slackdaddy

Since I had oil leaks at the valve cover(solved, but has a small weep still), looks like rear main seal, and at least 1 oil pan bolt,,,,
I am going to look at the CCV (Crank case vent),, I should not have this many leaks on a new engine.

I built this engine and was **** about specs and following the TSM to the letter. I "Did" have a very small groove on the crank journel where the seal rides, in fact I order and sent back 2 cranks before settling on this one.
The grove was VERY slight and for the most part could not catch a finger nail on it.

OldTires

Good luck. You are going all CSI on this oil leak.

Slackdaddy

I was able to get back under and look with a fresh mind.
I can see up between the rear of the block and the crank hub/flange, It is completely dry with nothing showing up with the black light, so I am thinking it is not the RMS.

I am leaning more towards the oil pan gasket, as the crank case ventilation is clear.
When I built the engine I used a Felpro "Permadry" oil pan gasket, as per the instruction I put a Small dab of RTV at the 4 corners.
All the videos I am seeing on Jeep 4.0 oil pan installs with the Permadry they are using a continuous bead or film of RTV across the whole back, on each side of the gasket.

Dropping the pan tomorrow, as it is the easiest thing to address,, if this does not cure it, I will pull the trans to pin point exactly where it is coming from.

Slackdaddy

So today I pulled the CCV fitting and hose to double check,, it was clear and passed air from the orifice when blowing into the hose.
While I had it out, I measured the CCV orifice and it was 3/32 (drill bit),, I went ahead and drilled it to the next size drill bit - 7/64 and put it back together.

I ran the engine for 25 minutes (10 at 1500 rpm, 15 min at 2000 rpm), then let it sit 5 minutes.
I had a piece of cardboard under it and had no drops of oil on the cardboard.

Using the UV light (oil still has dye in it), I had about a 1/4 drops worth on each side at the rear pan bolts, about 1 drops worth on the oil pan lip,, and 2-3 drops worth directly below the lip on the bell housing.
So all in all after 25 minutes not enough to hit the ground, and about 1/4 of the amount I got yesterday with the same test,, only difference was drilling out the CCV orifice 1/64 larger hole.

I am really up in the air if I should even bother messing with this oil leak,,, I need to finish this jeep project yesterday, and feel like I am taking 3 steps forward and 2 back for the last year.

Pics of todays "leaks"

Pass side rear pan bolt


Rear oil pan lip



driver side

cruiser54

I say go drive it.

Slackdaddy

YUP,,
OCD be damned!! LOL,, moved on to the Transfer case and 8.8 rear ,,

agreen

Sometimes the oil pan can be deformed a little when taking it apart and it'll be hard to seal after it gets slightly warped. Been down that road many times. Do it to yourself and it's not a huge deal. Do it to a customer and it's a whole different ball game.

MonacaYankee

I am having this same issue with my 1999 at 230k miles. I wonder if the rear elbow I replaced needs drilled out too. Will report back.

edit: I replaced the elbow because I broke it. The hole in the replacement was bigger than the old one so I did not drill it.

the oil leak was reduced from a dollar sized puddle to a 50 cent coin.

frank.longo86

did you check the oil filter adapter housing o ring. that travels down the block and drips in that area.