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Okay I know this topic has been much-discussed discussed. But I
have a late model 8N. Oil in coolant. Lots of people say head
gasket. Trouble with that being is there's no oil passages
through the head. I have pulled the head gasket. Block & head are
true no leak evidence anywhere. My question is there are oil
galleys through the block they must go through coolant passages
also. Anyone with knowledge of this.

It's very likely it is the head gasket.

What is happening is oil laden compression gasses are entering the coolant on a microscopic level. The oil accumulates over time and eventually shows up in the top of the radiator.

Does this have studs or bolts? If it has bolts, a set of studs will offer a higher pressure on the head gasket as they have fine threads on the nut end. If it has studs, remove them to properly clean, and for peace of mind replace them unless they were recently installed new.

Clean the block thoroughly, down to bright metal. Chase the holes with a tap. Go ahead and surface the head to clean up, even though it checks good.

Use a very thin sealer or aluminum spray paint on the new gasket. Seal the stud threads in the block with aviation sealer. Use hard washers under the nuts (they should come with the stud kit), light oil on the threads. Torque the nuts to 55 ft lbs. When up to temp, retorque the nuts. Slightly back each nut off just enough to feel it move without relieving the down pressure, then take to 55 again.

That should seal everything up. Might want to flush the cooling system with Dawn. Let the Dawn circulate with just water, try to float the oil up and out of the radiator. Flush it a few times, see if the oil is gone before flushing and draining, then add antifreeze.

(quoted from post at 19:01:39 10/19/20) Okay I know this topic has been much-discussed discussed. But I
have a late model 8N. Oil in coolant. Lots of people say head
gasket. Trouble with that being is there's no oil passages
through the head. I have pulled the head gasket. Block & head are
true no leak evidence anywhere. My question is there are oil
galleys through the block they must go through coolant passages
also. Anyone with knowledge of this.

Click to expand...

So what issue(s) are you having besides snotty coolant that brought you here?

WHY would you "pull the head" of a running tractor just because of snotty coolant?

Only place oil and coolant can mix in an 8N is the head gasket. But unless a lot more then likely to be from a old blown head gasket that left some oil in the radiator

Steve, I'd like to say I've never seen or heard ( might say John T can to) a more detail way of doing a job. I'm working on old tractors ( hobby), but get past spark plugs, even with manuals I have to ask. Thanks to all that help us that need a little light showing the right direction, not so much for those that gives lip service on how dumb some of are.

I agree with Steve and Old-head gasket. And especially about cleaning the bolts and bolt holes: dirty bolts won't torque properly. Mark.

Still no comments on oil tube running through block for oil galleys. If engine sets without coolant in it for a while can these deteriorate and if I do going through a water jacket introduce oil into the coolant I have been told this happens and at that point block is shot

It would have to Been over 35 years ago.for head gasket replacement. And I'm not talking just a skim of oil at the top top of the radiator. It puked quite a bit out the Overflow and there were still quite a bit in the top of the radiator

Steve thank you for your reply. This tractor was rebuilt 35 years ago has head bolts not stud. When I remove the head everything looked fine there were no signs of leakage anywhere. I was told buy an old mechanic but there is an oil tube that runs from the front to the rear of the motor and passes through coolant passages. He stated that if coolant is low in the engine and it said for very long these tubes can deteriorate and leak into the coolant. Any comment on list Steve? He says at that time the block is no longer usable

I'm not familiar with an oil tube inside the block.

Typically there is an oil galley drilled the length of the block that distributes oil to the main bearings. I guess it would be possible the galley could leak into the coolant, possibly if the block were frozen, or a casting defect.

I have seen many head gaskets that were leaking that showed no visible sign, especially when caught at the early stage of leaking. I would start there, since it is already apart, replace the gasket and see what happens.

There may be oil residue showing up in the radiator for a long time as it will tend to rise to the highest point, which will be the top of the radiator.

It could also have a cracked block and if that is so the engine is junk

No oil tube that I have ever seen or heard of in the 8N engine.

Its the nature of the beast... Flathead beast...

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