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Leaking Head Gasket

Discussion in '6.9L IH & 7.3L IDI Diesels' started by WarNose, Aug 8, 2019.

  1. Garbage_Mechan

    Garbage_Mechan Garbage Mechanic

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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”
     
  2. WarNose

    WarNose Full Access Member

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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.
     
  3. YJMike92

    YJMike92 Full Access Member

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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.
     
  4. YJMike92

    YJMike92 Full Access Member

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    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.
     
  5. 79jasper

    79jasper Chickenhawk

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    Not leaking while sitting on a stand, not being ran yet is a moot point.

    Sent from my SM-N960U using Tapatalk
     
  6. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    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.
     
  7. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    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.
     
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  8. pastorjeep

    pastorjeep Full Access Member

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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.
     
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  9. Tim McKay

    Tim McKay Registered User

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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.
     
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  10. Garbage_Mechan

    Garbage_Mechan Garbage Mechanic

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    If you are still hunting the oil leak try my crankcase pressurization test. Works every time!
     
  11. The_Josh_Bear

    The_Josh_Bear Full Access Member

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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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