IDI Cooling System Capacity?

Discussion in '6.9L IH & 7.3L IDI Diesels' started by mankypro, Oct 4, 2009.

  1. CDX825

    CDX825 filtration nut

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    Yup. I recommend Final Charge elc if you can find it.
     
  2. robw

    robw Registered User

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    To resurrect an old thread, my radiator barely takes 2 gallons before it tops off.

    How does one successfully flush a radiator with distilled water, and then get 4 gallons of antifreeze inside of it?
     
  3. Golden Helmet

    Golden Helmet Full Access Member

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    The block is holding a lot of the coolant. There are some block plugs you can remove that'll drain most of it out, one by the starter and one by the oil cooler according to this quick and lazy Google search. I can't give advice on flushing because I don't do it right myself, I just drain the radiator and refill.
     
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  4. robw

    robw Registered User

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    ^ perfect.

    I ran about 10 gallons of distilled water into the rig to flush the old coolant (which was fresh anyway), drained the drivers side and radiator, put in 4 gallons of Motorcraft gold and topped the rest with distilled water.

    CHEERS!
     
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  5. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    I think you may have a little bit too much antifreeze in there if you put in four gallons. You may want to check your freeze point. I think too much will actually raise the freeze point.
     
  6. Scooch

    Scooch Registered User

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    Going from a 50/50 mix of coolant/water to say a 60/40 of coolant/water will lower the freezing point not raise it.
    Also, the idi system is listed as around 7-8 gallons so 4gal of coolant assuming its concentrated not a premix is more then fine? Could even go up to 5gal and be okay in all reality.
    That's assuming all the old stuff has been removed or else who knows what the concentration will be
     
  7. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    When I used to work at a shop and was doing R&R work on these constantly, I'd put 6 gallons back in the radiator. That's after the had been replaced. The only things holding coolant were the heater core and the overflow tank. I really can't see the heater core as having much capacity. That's why I made the comment.
     
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  8. DrCharles

    DrCharles Full Access Member

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    I believe the lowest freezing point is at 2:1 (67% antifreeze, 33% water), something far below what almost anyone needs (like -74F). The 50/50 recommendation is basically to save money since -34F is enough in most of the US. Likewise for the boiling points.

    But pure ethylene glycol coolant will freeze at a surprisingly high temperature, somewhere around 0F if I remember right!
     
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  9. Oledirtypearl86

    Oledirtypearl86 Full Access Member

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    So strait antifreeze freezes at 10.4 f but a 60/40mux is good to -49f crazy how that works also it boils at 388.4 f
     
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  10. robw

    robw Registered User

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    I flushed the system with distilled water prior to adding 4 gallons, there was only a trace of previous coolant.

    You wouldn't know I flushed it, when I pull the cap you can see little bits of junk the water pump has to push around. =/

    Since the motorcraft gold has SCAs already, I wanted to play it safe with my turbo 7.3 and insure I had enough additives to prevent cavitation.

    I love the plethora of information found here, thanks everyone for all your input. :D
     
  11. renjaminfrankln

    renjaminfrankln Full Access Member

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    Buy the ford stuff on AMAZON about 10 bucks a bottle
     
  12. austin92

    austin92 Full Access Member

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    What I did was drive with a system cleaner for a few days then drain the radiator, fill with distilled water, drive, drain, fill with distilled water, repeat until I had nothing but pure water draining out. Took about 5 cycles/15ish gallons. After I drained the last time, I filled with super tech (Walmart) green strait coolant. Took about 3.5 gallons. Drove, drained until I could add about a gallon of straight coolant. I was aiming for 60/40 mix, got about -40 freeze point. I added motorcraft sca to coolant and a coolant filter a few months later with need release media.


    Sent from my iPhone using Tapatalk
     
  13. DrCharles

    DrCharles Full Access Member

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    I should also mention that water transfers heat much better than ethylene glycol. Another reason that the 50/50 mix is most commonly used. If you're towing heavy in a hot climate I'd stick to that, but in really cold winter -34F may not be low enough. I've seen that in northern Maine winters...
     
  14. Oledirtypearl86

    Oledirtypearl86 Full Access Member

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    I run a 50/50mix here in Montana and we hey temps of -40f for a few nights a winter and wind chill of -50f often I think starting everything once a day and letting it idle a few min helps a lot I had a time in North Eastern Montana it was -33 below at 3pm with a wind chill of -50 my truck idled for 2 days straight because I needed to use it for work
     
  15. Dirtleg

    Dirtleg Full Access Member

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    I've been getting the SCA additive, Motorcraft VC8, locally at both Advance and O'reilly. Less then $7 bottle.
     

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