[57WarChief]

Folks, hoping someone can give me good advice on where this oil/fluid is coming from in my coolant system. It's a 57 Chieftain with stock 347 and Hydramatic transmission and replacement Walker radiator with trans cooler fittings in bottom. I mention the trans cooler as someone told me it could be trans fluid. But to me this looks like oil-see pic.

Here's what I know so far: no water in the oil pan.-I drained to make sure and no signs of water on dipstick. Checked spark plugs before and after startup-dry, no moisture. Engine has had a recent history of overheating which is why we installed the Walker radiator and electric fan. After installing fan it overheated a couple more times during driving as fan would quit intermittently-turned out to be a faulty relay. Wondering if the overheating issues caused a gasket failure?

But, I can't figure why oil (or fluid) in coolant but not vice-versa. Anyone ever experience this and have advice?
https://apextoolgroup-my.sharepoint....web=1&e=IMUwOO

[rwfisher]

What does your exhaust look like cold start & when warm? Any evidence of moisture there?

[Goatracer1]

Your oil pressure is higher than your cooling system pressure so depending where the leak is the oil could be forced into the cooling system.

[57WarChief]

I see a little spray on the floor after it runs a minute but nothing excessive. it does idle really rough for a couple minutes till it warms up.

I thought about the oil being higher pressure; but is it under pressure as it drains back thru the head and be leaking around a failed head gasket? Or just as it's being forced thru the oiling system and thru the pushrods?

I'm trying to figure out where the most likely area it could be coming from: intake, valley pan, head gasket? Or somewhere else?

["QUICK-SILVER"]

Originally Posted by 57WarChief

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I thought about the oil being higher pressure; but is it under pressure as it drains back thru the head and be leaking around a failed head gasket? Or just as it's being forced thru the oiling system and thru the pushrods?

I'm trying to figure out where the most likely area it could be coming from: intake, valley pan, head gasket? Or somewhere else?

If it's engine oil it's not happening on drain back.

That engine should have oil pressure in the heads for rocker stud oiling instead of pushrod oiling.

Had a 350 Pontiac back in the 70's that did this. Pumped oil in the cooling system but no coolant in the oil. That leak was in the block. Never found out exactly where. Block swap did cure it.

Good luck
Clay