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Discussion Starter #1
I know theres an oil rife(passageway) near the exhaust ports. Does anyone know how to fix/repair an oil leak at the manifold or know if that area has a tendancy to warp after awhile? I tried replacing the gaskets but that didnt do much it still leaks like a pig. Any responses help :) Thanks for your time.
 

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Could be the valve guide seals.

And, the pre-IC engines were known to crack the head because of the large bore required for the fuel injectors. The IC engines had smaller diameter bodies.
 

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:whs x2. Its either the valve seals, or a cracked head. :eek:
 

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Discussion Starter #4
Thats a bummer, looks like I need to do some deeper information digging. Thanks guys.
 

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Discussion Starter #5
Has anyone replaced the vavle guide seals themselves or know if thats a fairly easy task to accomplish?
 

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Top-end lube oil flow . . . .

I know theres an oil rife(passageway) near the exhaust ports. Does anyone know how to fix/repair an oil leak at the manifold or know if that area has a tendancy to warp after awhile? I tried replacing the gaskets but that didnt do much it still leaks like a pig. Any responses help :) Thanks for your time.
There are no oil passageways near the exhaust ports of the Cummins head.

For the purposes of lubricating the upper valve-train, engine oil first comes up through the block adjacent to the longest head bolts (on the intake side). There at the block/head interface, the engine oil moves though a passage in the head-gasket over to the bore in the head for the long head-bolts.





At that point, the engine oil moves up through the head flowing around the longest head bolts (those closest to the intake). There, where the rocker arm pedestals meet the head, the oil flows from the head-bolt passage over and into a passage in the rocker-arm pedistal.





From there, the engine oil flows through the pedestal and into the rocker-arm's shaft where it lubricates the rocker-arms. Further, some of the oil flows through a small opening in the top of the rockers where it runs in a small groove over and onto the portion of the rockers that rides the valve stems. That's where the rocker-arm / valve gets lubricated.




- Have you cleaned the engine so as to see the oil flow from the engine?
- Are you able to determine exactly where the oil seems to be coming from (where are you seeing the oil on the engine)?
- Are you talking about an internal oil leak that seems to flow out of the exhaust manifold gaskets?
Are the valve-cover gaskets in good shape?
 

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Discussion Starter #7
After cleaning it all off, It showed leaking from the 2nd and 3rd ( If your looking straight at the engine) exhaust manifold ports and also alittle around the same valve covers. I havent taken any of the valve covers off to check their gaskets.

Thanks for the clarification of the oil lubrication :D
 

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If it is the v/c gaskets, most likely they are hardened where they contact the head.
 

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I would replace the valve covers first. If they have never been done, It could be one of those things that tricks you into thinking it is much more serious, and it only cost about $20 I think for all of mine, and Autozone had them in stock.
 

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Discussion Starter #11
Sounds good. Hopefully its that simple. I really dont know when they were last replaced. I'll give a call and see. Thanks all. :)
 

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NOTICE!

Whatever you do, don't buy the Black valve-cover gaskets (FailPro?), get the genuine Cummins Grey ones.

The black ones become brittle and fail very quickly. :bang

The grey Cummins gaskets are made of a better grade material and typically can be wiped-down for reuse for years.
 

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I remembered pictures that I took when the leak first started. Maybe they'll help.
I dunno . . . . :confused:

That may very well be something going on in those cylinders as one can see the weeping of that exhaust manifold flange in the first image.

- Could be a worn/failed valve stem seal.
- Could be an injector tip whacked in some way if not simply an injector peeing instead of fogging the fuel.

Don't know the mileage of your truck, but you might consider pulling the injectors and have them rebuilt and pop-tested (if they are the final word in your fueling plans).
 

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Discussion Starter #14
Felpro? Their Blue.

The gaskets I took off were pretty stiff
 

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I dunno . . . . :confused:

That may very well be something going on in those cylinders as one can see the weeping of that exhaust manifold flange in the first image.
Looked like v/c gaskets. It appears to be running down the side of the engine. Replace them and steam clean the rest of the engine.

There is a chance the v/c gaskets could still leak after installing new ones.
 

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Discussion Starter #16
If you have no access to steam cleaning what else could you use?
 

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Go out and find some Oil Eater. Get a spray bottle, and spray everything down at a car wash full strength. Don't dilute it at all. Won't damage anything. It isn't a harsh toxic chemical like most cleaners are. Let it sit for a few minutes and with the engine cleaner setting, it should come right off. Depending on how heavy the build up is, you might need to do it again.

www.oileater.com Our local Farm and Fleet store carries it.
 

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Discussion Starter #18
Ok all cleaned up and new v/c gaskets installed stopped the leakage from the 2nd and third v/c back from the front. However oil is still seeping out of the 3rd exhaust port back. Trucks pretty near 210k in mileage. Could that be injectors, like BC847 suggested or the valve stem seal. Any good way to know for certain, or is tearing into it the only way to find out? Thanks all so far :)
 

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Easiest way to tell between fuel and oil without tearing anything apart would be to get a bottle of leak dye to put in the oil. Get a black light (or lighter black window tint over a strong flashlight).
 

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Discussion Starter #20
Any garauntee that the valve guide seals would fix the leak in this case?
 
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