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Detroit diesel Anti freeze

Discussion in 'Technical Discussion' started by ArielM, Jan 10, 2012.

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  1. ArielM, Jan 10, 2012
    #1
    ArielM

    ArielM Senior Member

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    It has been a couple years since i last changed the antifreeze in my 8v92s. I plan to drain the system and replace with new anti freeze but the current coolant in my system is green and the new detroit coolant is pink.

    I know i am draining the system but some of the older coolant will surely be left in the system. Is there any harm in using Prestone type antifreeze with the correct ratio of detroit SCA additives? According to my local detroit dealer there isn't a problem but i dont fully trust part retailers.
  2. SeaEric, Jan 10, 2012
    #2
    SeaEric

    SeaEric YF Historian

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    My DD guy agrees. No problem mixing them. He did so on my boat after a complete hose replacement. I trust him completely.
  3. Capt J, Jan 10, 2012
    #3
    Capt J

    Capt J Senior Member

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    I would change it ASAP, as with the 92 series O-rings it should be done every 2 years. Drain the antifreeze you have, fill the engine with straight water, run it for 30 minutes, drain it again and then add the DD additive........
  4. d_meister, Jan 11, 2012
    #4
    d_meister

    d_meister Senior Member

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    There have been a lot of changes in coolant chemistry in recent years. The orange coolants are the extended use formulas, and the green ones tend to be the old ethylene glycol formulations. The extended formulas can be either 2 year or 5 year. In mixing some of these with ethylene glycol, a gel can form, so it is best to flush the system as best you can. If there is a heat exchanger for the house water heater, that should be flushed as well.
    Newer engine manuals stress the ph of the coolant should be checked and properly adjusted. It is well worth the few bucks to use distilled water in the coolant, as some muni water systems can be acidic or alkaline, not to mention loaded with minerals.
  5. Capt J, Jan 11, 2012
    #5
    Capt J

    Capt J Senior Member

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    Also, DD sells a little bottle of test strips for the DD red coolant additive, get those to verify your concentration......obviously after running the engine 30 minutes to circulate it.
  6. Capt MAP, Jan 24, 2012
    #6
    Capt MAP

    Capt MAP New Member

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    I have two 1990 12v92s 1990 vintage in a Hatteras 70. This is first I have heard of changing coolant. I run in S Fl. Can you educate me? I was going to remove heat exchangers and have them descaled. Then add new coolant then.
  7. jhall767, Jan 25, 2012
    #7
    jhall767

    jhall767 Senior Member

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    DD specs probably recommend coolant change every 2 years for that engine. Also new thermostats every two years. There is an on-line cooling system cleaner that you add to the engine and then run it for a few weeks prior to flushing. You do not want to use the off-line cleaner. If the boat will not be exposed to freezing temperatures you can just use water and an additive that prevents corrosion.

    This does not affect the seawater side of the heat exchanger which may need to be cleaned.

    I suggest you get a set of service manuals for the engines and refer to them.
  8. Capt J, Jan 25, 2012
    #8
    Capt J

    Capt J Senior Member

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    Also get the DD coolant ph test sticks and test the coolant additive to water ratio after running the engines long enough to mix everything (30-60minutes) and add more additive or water for the PH to be right, also test it every 6 months.