Can a Flathead get oil in the radiator?

[hombres ruin]

Hi guys. We hear of water in the oil but can a Flathead get oil in the water. The reason I ask is this. I have a stock 41 coupe. New radiator and new top and bottom hoses. They have been on the ride for about year and a half . The rad is aluminum. It has distilled water and water wetter in it. I have a 7lb cap and at times I get what looks like dirt/mud under the cap it’s greasy to the touch.Its about a dime maybe less in size and watery not much at all. It’s on the most prominent end of the cap . The block is original and has 19800 miles on it. Looking in the rad I see what looks like scale ,pic enclosed. It’s been noticed by me for a while. I drained the radiator last week and no oil was present in the water. I flushed the rad out and filled it up. I did a combustion gas test with the kit and it was negative, I am not losing any water nor losing any oil . No water out the tail pipes nor smoke . It runs great and never has overheated .it has original heads and no water in the oil pain. Am I dealing with crud from the block or oil? Am I over reacting? Thanks for the advice/help

[Jack E/NJ]

Yes but unlikely. Crud probably. And probably yes. 8^) Jack E/NJ

[19Fordy]

Not to worry. I bet the Water Wetter has some chemicals in it that make the water slippery.

[rotorwrench]

Some forms of fungus can grow in just about any environment. So it could be that. Ethylene glycol anti freeze doesn't promote growth of fungus very much but water with small amounts of added oil or surfactant may.


When an engine design had an oil carry through on a flange that is near a coolant passage then there can be cross contamination due to a gasket leak and more so if there is a cross contamination leak involving a combustion leak at the head gasket. The head gasket situation doesn't work with the flathead Fords unless there is a piston ring problem. Cracked blocks are generally the other way around with coolant in the oil. The coolant system is generally always a lower pressure than the oil system but a water leak will go right down into the pan. If the oil pressure leak is into the coolant passage (which is almost non existent in flatheads) then the oil can get into the coolant.

[hombres ruin]

Thanks for the reply’. Seems like I have a dirty block. I don’t have water loss nor water in the coolant. Seems extremely hard to get oil in the coolant . And it may well be a fungus as the stuff in the rad doesn’t look like oil globules at all. And then recently drained rad showed no oil at all

[V12Bill]

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You could try to clean the block by draining the water and putting in white vinegar for a few days of running to clean out the crud. You say the engine is stock but then you say you have an aluminum radiator. I'm not sure if the acidic vinegar would eat at the aluminum. Why did you install an aluminum radiator?

[38bill]

Would a bad seal in a water pump let oil get into the water?

[lotsagas4u]

Irontite thoro-flush will clean it out.

[blucar]

If you are running an aluminum radiator you should be using modern coolant made for use in engines that have aluminum components in lieu of a water mixture. Since the original water pump seals are not a good idea with modern coolant, you should consider having your water pumps rebuilt by Skip Hanley.
Many people are not aware of the fact that the original Ford water, pumps, '37-48, are internally lubricated by the engine oil which is actually a total loss type of system.

[danliveshere]

So are you saying old pumps use water. New pumps with modern seals use modern coolant?

[Jack E/NJ]

Originally Posted by danliveshere

So are you saying old pumps use water[mixture]. New pumps with modern seals use modern coolant?

Yeah, I'd like to hear the answer to this one. I assume the water mixture referred to is water with either methanol like the antique Zerone or ethylene glycol like the antique Zerex. I just use the new ethlylene glycol stuff "specially formulated for modern cooling systems" in all my antique cooling systems without apparent adverse reactions.....yet Jack E/NJ

[hombres ruin]

Originally Posted by blucar

If you are running an aluminum radiator you should be using modern coolant made for use in engines that have aluminum components in lieu of a water mixture. Since the original water pump seals are not a good idea with modern coolant, you should consider having your water pumps rebuilt by Skip Hanley.
Many people are not aware of the fact that the original Ford water, pumps, '37-48, are internally lubricated by the engine oil which is actually a total loss type of system.

I am using original water pumps I believe. I am using water and water wetter which is completely compatible with aluminum radiators. I am not using anti freeze. Are you saying that the additive water wetter isn’t a good idea for stock pumps? And only plane water is?

[Blownflatheaddeuce]

Mate, bolt on a 4-71 lung - it'll fix EVERYTHING

[G.M.]

I would say if you have a badly worn pump shaft or worn out bushings
you could get oil in the water, using thin oil would increase the problem.
This would be on original bushing type pumps. If you had the problem
with bearing type pumps you could plug the oil hole in the block on the
pump mounting surface. The bearings are sealed and get no lubrication
from engine oil. G.M.

[hombres ruin]

Update so far .. I drove the 41 all day Saturday last week and I came back today and opened the rad cap and their was oil, it has to be. It was slippery and an oil feel to it and consistency. It was a very small amount on the cap. Flashlight in the rad and no oil on the surface anywhere . Took a 20cc syringe (I work in the med field) I drew 20cc of water to look at it and no oil. Block test was negative. No water loss. As GM states above could this be a water pump issue? Are they lubricated from the engine oil ? Any advice would help.

[petehoovie]

Yes, the water pumps in your '41 are lubricated by the engine oil. If you have a spare pump to inspect you can see the oil hole on the back side of the pump just above the bearing....

[Ross F-1]

Originally Posted by Jack E/NJ

Yeah, I'd like to hear the answer to this one. I assume the water mixture referred to is water with either methanol like the antique Zerone or ethylene glycol like the antique Zerex. I just use the new ethlylene glycol stuff "specially formulated for modern cooling systems" in all my antique cooling systems without apparent adverse reactions.....yet Jack E/NJ

As far as I know, using the newer style coolants (Dexcool and many derivatives, generally show "phosphate free" on the jug) in a totally cast iron engine is just fine and has some advantages. If there is aluminum in the system (radiator or heads) then you definitely want the newer coolants.

I have a newer Ford ('15) and there are no fewer than 5 different types of antifreeze used for '15 Fords. Fluorescent green, orange, red, yellow, etc. Some are specifically for turbo engines, some for diesels. The differences are in the chemistry used for corrosion control (organic acid technology vs. hybrid organic acid technology).

[hombres ruin]

Seems that the water pump is the culprit since it’s only trace amounts of oil the bushing may be worn out in the pump. I will send them to skip and take it from there I guess. Don’t know what else it can be

[blucar]

It is very common to overlook the internal lubrication system of the EFV8 water pumps.
Many years ago when the flat-head Ford engines were common and detergent oil was not sludge would build up in the block causing all kinds of problem, one of which was the oil passage through the block, which was un-pressurized, gravity fed from the engine valley.
It was very common to remove water pumps that had been leaking coolant via the shafts to find that they had not been receiving lubrication for a long time. Prior to replacing the worn out water pumps it was SOP to run a wire through the block to clear the oil channel.. Many people did not bother to do this, because they did not know there was an oil channel through the block.
As I recall the early 21 stud engines had grease zerks on the water pumps.

[hombres ruin]

I am still getting some oil which I know is oil on the under side of the radiator cap and smal traces on the water surface. The drives side pump has some play on the pulley head where the belt goes it moves left to right and has a build up of oil on the arm that is used for the motor mounts .. the passenger side has none of this. I spoke to skip and he said the bushings are worn and could be the problem and letting oil into the water. I will rebuild them and see what happens .. what else would it be ?