RockyMtn96XJ

Hey y'all, my last post was about my distributor and an oil leak, but but I found the leak was from in between my block and head. I used 2 little bottles of oil dye and cleaned the passenger side of the block real good, took a 5 minute drive and then could clearly see the oil dye in a straight line nearly front to back btwn the block and head.

My curiosity comes in and I wonder how this happens. I now know about the oil passages on that side of the block, but what causes it to start leaking? Time? Gasket failure? Too much oil pressure? Mine seems to leak more than I'd like to just keep an eye on it..... No clue when mine started to leak but for the longest time I thought I've had a rear main seal leak, and it's just gotten bad enough to notice it wasn't the rear main.
Thanks for the theories!!!

BruceB

Actually I had the same problem....I chased it down and it seems on some of these motors after a couple of hundred thousand miles, the head develops a slight warp. Some here suggested to do nothing if the motor is running well and worry about it when the motor needs going in to for a major repair. I seem to have an ODC thing about oil leaks and prior to this weeping ever started I had already replaced the Rear Main Seal, Distributor gasket, valve cover gasket, oil pan gasket, oil filter adapter seal and O-rings. I tried using ATP Automotive AT-205 Re-Seal. It helped....Then it only leaked a bit after a 2 or 3 hour highway speed drive, I changed my oil from 10w30 to 10w40 and that stopped the weeping completely.
Hope this helps.

lawsoncl

You're looking at the seam between the block and the head on the passenger side? Any leak from above tends to hit that seam and run sideways. But I have seen a number of engines with a slow oil weep coming from the seam, including my previous engine. There are no pressurized oil passages there, just the push rods.galleys. So a very slow leak is just a cosmetic issue.

RockyMtn96XJ

Yeap, thats the seam that is leaking. Definitely a fresh leak from that spot and not from the valve cover. I have more oil spots in the driveway than I'd like, so my problem is either leaking too much, or I have 2 leaks hahaha....
I need to give that side of the block a REAL good degreasing/steam clean and check my oil adapter and other prone areas. I also bought a new oil pan gasket and rear main because I thought my leak was from there (rear main) when I first noticed the leaking on the concrete. Lots of oil splashing back onto trans pan etc. But I also see drips on my track bar and other spots under the area thats leaking from btwn the head and block.
My last oil change was about a 1.5 qts low when i drained it. Probably more but i dont remember, i just know I was shocked and new I had a big issue.

I can move up to 10w-40 and see how it goes, along with the addition of some AT-205. That may buy me some time.
Good to know those oil passages aren't pressurized.

How long does a head gasket take for a well groomed shade tree mechanic? I saw one guy did it in about 4 hours, and some other guy said it took him like 20 hours from what my brother told me. I would be much closer to the 4-6 hour time frame. But I dont feel like rushing through it.

BruceB

Getting to the head is the worse part... Both intake and exhaust manifolds need to be removed, then the fuel rails and all.....removing and marking all the rocker arms and push rods so when you replace them they go back to the same location. More importantly, if you are removing the head, take it to a machine shop to check how warped it is. A new head gasket may not be enough to fill the warp gap. Then if they machine the head flat, I do believe that a thing called preload on the push rods come into play, but some one else will have to go down that rabbit hole with you for a solid explanation. Probably many Y-tube videos on removing the head.....check them out...

RockyMtn96XJ

Heck, all I was thinking about is a head gasket that has served its purpose and now needs to be replaced. Hadn't thought about the head possibly needing milled..... involving pushrods and pre-load.
I do have 227,xxx miles on it, but never over heated that I know of. I've owned it for almost 5 years and the previous owner was a retired military mechanic and took superb care of the whole jeep. I can guarantee I drive the jeep a little harder than he did, but I doubt I'm lifting the head or even blowing out that gasket since it isnt pressurized.

Yes the part I am not looking forward to is the intake and exhaust. I put in a horseshoe intake and an ebay header. They fit together fine now, but it took some convincing and a little materiel removal on the intake. There are 2 bolts I think that are a REAL PITA to get to. I think I remember making a special wrench for it.

Thanks for all the insight!

bluejeep2001

Its a weekend job, no one can do it in 4-6 hours. Also remember that you have to put permatex high temp sealant on the front drivers side headbolt where it goes through the water jacket. I see your in colorado, its probably snowing..you doing this in a garage or outside. Also if your over 40, you are not lifting that head by hand yourself. . The back drivers side headbolt usually doesn't clear the firewall overhang so it has to be removed and installed in the head prior to placement. I use a big rubberband to hold out of the way... That 96 head is very rubust, usually not many issues with warping , and then its mixing coolant with the oil...it suprising that its only leaking oil in the pushrod galleys, all thats in there is what drains down the pushrods

RockyMtn96XJ

I thought half a day sounded really fast, even if I have done plenty of work on the top like new injectors, intake, exhaust header, etc.... everything except head removal. Luckily I have a spare vehicle I can drive if it takes more than a weekend. But cant drive that camaro in the snow,... Have to plan around the weather now. Even with my air tools I thought 4-6 hours sounded real fast.

Permetex on head bolt, check. Thanks for that detail. Good to know now instead of finding out later, even if I saw it in a video, having it it in my head now helps not forget.

Yeah we had about 8" where I live in the suburbs this last weekend... I have room in the garage, but dont mind if its sitting in the driveway. I'll just set up my canopy tent thing and hang some tarps around the sides with my bullet heater blasting in there.

I've heard that iron head isnt easy to remove, probably since its so long and made of iron. I am 44 but can guarantee that head wouldnt be too heavy for me....... UNLESS it's difficult to get out because its long and you need 4 hands for leverage to get out from under the cowl? I would just be worried about how to work it out of there, and if thats the hard part then I can see where the weight would play a factor.

I'm as confused as everyone else on the leaking location. I've never heard of oil leaking through a head gasket, especially if its just gravity at play and not pressure. except on these motors apparently. I dont even understand how it happens even with 227k miles. I'm not yet familiar with the head gasket material, is it all metal or is there rubber somewhere in there also that can fatigue over time? Just never heard of this type of issue.... a leaking head gasket but the engine still runs fine. No signs of oil and coolant mixing ever. I guess if the leak spot is so small that it keeps pressure because of oil viscosity, it'll run fine.

I just remembered the old owner did the oil pan gasket and rear main seal the year before I bought it from him. Founds those receipts from the shop in the haynes manual he gave me with the jeep.

bluejeep2001

If your going to lift by hand, take the hood off...easier to get in there with good body pos. Felpro makes a 530 SD severe duty and thicker head gasket. I think im running that now. Are you absolutely sure its not running out of the valve cover and just pooling on the block edge by the head gasket interface thats way more believable...silly question...have you had the valve cover off and checked the torque of the headbolts that run down that side of the block...should all be 110 ish.

RockyMtn96XJ

I'll take one more good look at it this evening with my blacklight to ensure where its leaking from. I'll get some pictures as well.
I've not taken the valve cover off nor am I sure if it has ever come off. I have a cheap Am-Pro ft lb torque wrench that I inherited, but I dont trust it too much. I dont like the scale because its small and doesnt take many twists to adjust from min to max. I think its like 50-180ft lb. or something.

I wonder if there is a place I can take it to see how accurate it is and what it's % of inaccuracy at the top and bottom of the scale.

bluejeep2001

For a new install I would want the torque wrench to be fairly accurate..to see of the current bolts are loose, pretty tight with it or any breaker be be good enough we are not talking leaks because they have loosened to 80 or 90 but because several might have loosened to 20 or 30. If you have a machine or speed shop in the local area, they would probably have the ability to check it for you

RockyMtn96XJ

Not the best photo but it's one from last week.

bluejeep2001

Well thats some kind of leak..just to confirm there is no oil under pressure over there, just what drains down the pushrod on the outside . Whatever lets that much oil freeflow must be pretty big. Before you pull the head, confirm those headbolts are at least man tight. If so it looks like your pulling the head. Rock auto gives some pretty good photos of the head gasket just so you can see what might be wrong. You might want a new set of head bolts..only 40-50 bucks.you have no way of knowing the life history of the ones in there

RockyMtn96XJ

son of a.......

bluejeep2001

Not sure what your 2nd black light is showing...most of my black light pictures are either Jimi or Jerry...lol