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Oil leak questions

Tony_SS

NAXJA Supporting Vendor
Location
Washington MO
So I sealed up behind the valve cover where it was leaking. Test drove, its dry back there, but right after I park it I still get a saucer plate size of fresh oil right away then it stops.

Can the oil leak from where the head meets the block? I dont feel any oil on the back of the head, but the corner stud (with ground wire) where it meets the block I feel oil there.

Should I recheck the torque on that bolt? Can it leak oil in that headgasket area?
 
If you haven't already done so, crawl under there and shine a light between the back of the engine and the front of the tranny. Reach up in there with a rag and wipe everything off...clean. Then go for a little drive, not just around the block, but a little 10 or so mile road trip.

Then crawl back under with a light and look at the area you cleaned off. If there is oil there you more than likely have a rear seal leak. If there is oil around that head bolt (the ground bolt) then the valve cover is still leaking, albeit just in that on spot. The rear head bolt is surrounded coolant galleries, not oil. It's actually more likely that you'd have an oil leak on the passenger side, since that's where all the oil for the head is, pumped up through the push rods as they go up and down.

It's also possible that your oil leak is tranny fluid/lube leaking from the bell housing unless you're dead sure it's oil.
 
Its a new engine so I am doubting a rear seal leak?

It is for sure oil, nice new clean oil.

I guess it's possible it leaking from a tiny spot from the valve cover still but the ground wire head bolt, but I'm just not feeling it around there, just where the head meets the block. If it cant leak oil from that part of the headgasket, it has to be the valve cover still I guess, maybe in that one little spot. But a saucer plate size is a lot of oil considering. It it will do that within an hour after it's parked, then it's done.
 
 
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, people on Jeep forums who can’t see your Jeep from where they’re at, 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. "$hit 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.
Revised 02-26-2013
 
Ok, poked around a little. Drove it, came back, crawled underneath, I need see oil dripping off the back exhaust manifold bolt. So I have to assume its leaking from the stupid valve cover on that side. So this will be my 3rd stab at it...but the good news its not leaking down the back of the head, just off to that one side.
 
Get a Fel-pro rubber gasket for the valve cover. Remove the valve cover, scrape all the "sealant" off the head and the cover, make sure the valve cover isn't bent or tweaked, install the Fel-Pro rubber, with no sealant...follow the torqueing sequence and torque specs, never worry about the valve cover again.
 
Get a Fel-pro rubber gasket for the valve cover. Remove the valve cover, scrape all the "sealant" off the head and the cover, make sure the valve cover isn't bent or tweaked, install the Fel-Pro rubber, with no sealant...follow the torqueing sequence and torque specs, never worry about the valve cover again.

That's what I did the very first time and I had it running down the back of my head.

It's a Dorman valve cover but I checked on a few flat surfaces and it appears flat....but maybe it's not?

I would like to get a factory valve cover but its big $$$ and used ones could be bent or jacked up with crud. Its a new engine so I dont want to run some gunky parts on it.
 
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