Leaking Head Gasket

Garbage_Mechan

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I had a 90 F250 in my fleet, bought it in 94 from the original owner. It was the landfill managers truck, later landfill crew truck. The head gaskets seeped just enough there was always a green drop hanging there. Ran this truck till we left in 2014, never touched a thing other than pump, injectors, water pump etc. Every new PM guy worth a darn would always hunt me up to tell me about the head gaskets and I would alway say “ok we will keep an eye on them”
 

WarNose

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On the coolant leakage.... while it is not common for this to leak on a new build, it isn’t uncommon for there to be a coolant seep and some accumulation at the very rear outer corner of the head. Did the block get decked?? Head?
The heads were decked but not the block. The machine shop said it didnt need it. And it didnt leak when pressurized to 30 before it was installed.
 

YJMike92

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Oil may not be under pressure in the head gasket area but does return to the crankcase through the head drain back areas. Coolant is under slight pressure. You might try a retorque on that head. Lossen one head bolt at a time and retorque it in the original torque sequence. It couldn't hurt at this point. If that doesn't do any good and your sure its the head gasket pull the head and see whats going on. While the head is off the cooler might be easier to seal as well.
 

YJMike92

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The heads were decked but not the block. The machine shop said it didnt need it. And it didnt leak when pressurized to 30 before it was installed.


Another thought. Did the machine shop mill your heads properly? I have had several heads ruined by machine shops. I always run a straight edge across the head even after a resurface.
I had a set of Subaru heads with such a rough cut that they leaked coolant right through the machined groves.
 

IDIBRONCO

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Will oil come out the dipstick tube if the crankcase becomes pressurized?
The only time I've seen this was when a F'ing drunk put standard pistons in a .020" over block. It rattled extremely bad and did blow oil drops out of the dipstick tube. Other than that, I haven't seen it. At least not on a fresh engine, now a worn out one, that's another story.
 

IDIBRONCO

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The oil is dripping off the edge of the head gasket that protrudes outside the motor. So it is definitely leaking from somewhere above the oil cooler. Although the oil cooler is also leaking a bit. Maybe it is leaking from behind the intake, where I tapped in for the oil pressure gauge. I can't see back there for anything.
Before you tear the engine apart, get an inspection mirror of some kind and look back there with the engine running. You'll probably need to use a light to see clearly. I'd guess that the oil leak is coming from there or the valve cover gasket. Find this before you worry about the coolant leak. One step at a time.
 

pastorjeep

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I had the same thing happen on an 89' 7.3 I rebuilt. Started leaking withing a few miles. Turned out I had knicked the gasket while installing the head and missed it. :) Hope it is nothing more serious for you.
 

Tim McKay

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Recently had a coolant leak in the same location on a non-rebuilt motor, 150k miles on it. I was advised to retorque it, and monitor. I did so, and its been maybe 3 weeks, and all is dry.
 

The_Josh_Bear

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+1 on retorque assuming that is where the coolant is leaking. I used dye to verify I had leaks coming down both heads and even posted wondering about it. The consensus was NOT to do it; but a very few saying it's fine, and was SOP at Ford shops around the 30k mark even on factory engines.

So I got after it and now probably 10k later I leak almost nothing and what is missing I haven't determined if its head gasket or something else.

Although I have a technical question about the retorque, I'll post it on it's own and see what the response is...
 

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