blown HG cleaning out heater core and radiator

Discussion in '80-Series Tech' started by silverhorse, Mar 12, 2010.

  1. silverhorse

    silverhorse

    Messages:
    829
    Location:
    Pensacola, Fl.
    This may be hard to believe but, I have a blown HG. :rolleyes:

    The motor is out of the vehicle for a rebuild. My heater core and radiator are full of oil. What is the best way to clean them out? TIA
  2. elhombre

    elhombre

    Messages:
    603
    Location:
    Canyon Lake, TX
    Did the engine over heat and then blow? In other words, how do you know that the radiator is not clogged up and the main problem?
  3. Shipwreck

    Shipwreck

    Messages:
    420
    Location:
    The Saratoga slums, CA
    Yes, how do you know that the HG is blown? There are other ways of getting oil into the cooling system; such as a leak at the oil cooler on the side of the block.
    Since the engine is out for a rebuild the HG discussion is moot, but for others who find oil in the coolant, you cannot automatically assume a blown HG unless there are other symptoms as well.
    To flush the radiator and heater core while they are removed, is similar to flushing with engine in place. Plug the outlets, fill with muriatic acid solution/commercial radiator flush and hot water. Let sit for awhile. Rinse. Repeat.
  4. lacruiser

    lacruiser

    Messages:
    874
    Location:
    Los Angeles

    Don't do this if your radiator is aluminum. You won't have a radiator left if you do.

    Since the engine is out, I'd take the radiator out to a shop and let them go through it. It's not a big deal to remove the top tank, rod it out, then replace the tank with a new one. If the rad hasn't been touched since new, it's probably due for this service anyway.

    You can use the acid on the heater core, but why? Is it plugged? (was the heater working fine before you removed the engine). If it's not plugged, just hook up a garden hose to one end, and flush away. That will remove pretty much everything from the core. Then, to get rid of the oily residue, pour in a solution of detergent and water (or pure simple green works great as a degreaser), let it sit overnight and then flush again. Rinse/repeat, and you've got a nice clean heater core.
  5. mkfour

    mkfour

    Messages:
    769
    I'd just get a new radiator. 15+ years is a good length of service.
  6. CJF

    CJF

    Messages:
    6,561
    This bears repeating...
  7. silverhorse

    silverhorse

    Messages:
    829
    Location:
    Pensacola, Fl.
    I bought the truck as is. The PO said it was blown? I'll tell ya this, when I tore down the motor it had anti freeze in it. Stained the crank in fact.
  8. silverhorse

    silverhorse

    Messages:
    829
    Location:
    Pensacola, Fl.
    "or pure simple green works great as a degreaser), let it sit overnight and then flush again. Rinse/repeat, and you've got a nice clean heater core."

    And it will smell GREAT! :D
  9. Michael Hanson

    Michael Hanson

    Messages:
    7,380
    Location:
    Plano texas
    Id go new rad.too,cheap insurance with summer coming on. Mike

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