Heater core fail

Discussion in 'The Garage' started by D.T., Jan 23, 2013.

  1. doxiedog

    doxiedog Been here awhile

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    I have run my heaters once,
    for 5 min. in the summertime.
    Just to change the fluid in the core.
    Never had one fail on me.
    The cost is zero. :D
    #41
  2. oldxr

    oldxr Long timer

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    Semi-retired autotech-I have changed out a pile of heater cores.The GM cooling system tabs work great-last time I used some it was on a H1 Hummer with a leaky head gasket.Caddy dealers always have them.The reason heater cores fail is from not changing the coolant-it turns acidic after awhile and the heater cores are aluminum on late model cars & pu's.Pulling the dash isnt that hard-just time consuming and you need to be parked in the middle of a garage because both doors will have to be open.Follow a service manual.A good set of torx bits and a 1/4 drive socket set with extensions will be needed.Sometimes I pull the seats-you make up the time spent on this in the end.
    #42
  3. _cy_

    _cy_ Long timer

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    working under the dash is top of list of worst jobs to do.

    this is why I'll always install Bars Leak long before any problems becomes due. even if my cooling system is not leaking. Bars Leak also conditions coolant and lubricates your waterpump.

    ethylene glycol the main ingredient in anti-freeze really doesn't wear out. but anti corrosion additives do get depleted. installing Bars Leak helps maintain coolant.

    only use the original pelletized version of Bars Leak. adding something wrong to your cooling system could really screw it up major.

    not a proponent of changing out anti-freeze just to renew anti-corrosion additives. have ran the same anti-freeze for 20+ years on multiple vehicles with zero problems. but they all had Bars Leak installed right from the beginning. then anytime radiator hoses were renewed. Bars Leak reinstalled.

    ---------------------------
    How to Check for Electrolysis Corrosion
    With the engine running and at normal operating temperature, use a digital voltmeter to check for voltage between the coolant and the battery negative (-) cable. Carefully remove the radiator cap or coolant reservoir cap (use a rag and open slowly as the system will be under pressure and hot steam may blow out of the opening). Insert the positive (+) voltmeter lead in the coolant, and touch the negative (-) voltmeter lead to the battery negative post. If you see a zero reading, that's good because it means there is no stray electrical current flowing through the coolant. But if you see a reading of 0.300 volts (300 millivolts) or higher, you've got electrolysis and potential trouble.


    [​IMG]

    checking ph
    [​IMG]

    Snap-on cooling system pressure tester to make sure everything is holding tight
    [​IMG]
    #43
  4. AviatorTroy

    AviatorTroy Long timer

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    There is fluid circulating through your heater core all the time, it just blows hot air out when the door opens inside the duct.
    #44
  5. rapidoxidationman

    rapidoxidationman Easily trainable

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    unless there's a valve on the heater water line... then it only blows hot air when the core is hot. No hot water flowing, no air gets hot as it goes through the core.

    You might be right about the GM system of making hot air, but such is not the case on my old Benz or any of my previous toyotas.
    #45
  6. Fixnfly

    Fixnfly Been here awhile

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    I did the heater core on a 99 S-10 a few years ago. It ranks pretty high on the pain in the ass list. Lots of vacuum hoses to disconnect and keep track of, lots of screws in places no screws should ever be. During the 8 hours I did this, I made up a few new curse words and threw a few tools across the garage. It's one of the many reasons I would never even consider buying another GM product.
    #46
  7. KeithinSC

    KeithinSC Long timer

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    I'd be doing the job myself, but I have a heated shop. You will want heat, as all that plastic on the dash and hire harness connectors is brittle when cold.

    Good luck.
    #47
  8. Benesesso

    Benesesso Long timer

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    Some of that junk plastic is brittle here in Phoenix in the summer. But when a company is pinching pennies to pay those huge salaries/perks to upper management, why spend a few for decent plastic? Every beancounter needs his high dollar lunch! :1drink
    #48
  9. Benesesso

    Benesesso Long timer

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    So you believe that Bars Leak renews the corrosion protection? Any idea what chemicals it uses to do so?
    #49
  10. Anorak

    Anorak Woolf Barnato

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    Turmeric and Ginger with a smidge of polyethylene glycol to make it even more enjoyable.
    #50
  11. H96669

    H96669 A proud pragmatist.

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    Interesting the Bars's leak corrosion protection.I never knew that. Looks like I may dump some in the bush car, don't think the antifreeze has been changed in 10 years.:wink: Just so happens that I have some here, no need to spend money on that car, it is a Toyota after all.:wink:

    Rhyzex???

    http://www.barsleaks.net/how2works.html

    My 78 GMC van was shooting antifreeze through a spark plug hole. Bar's leak fixed it and for many years. Enough time to drive it all the way back east and come back fully loaded, then go to Mexico and was still fine when I sold it many years later.

    Not so on my 88 Chevy van, same problem and the engine blew up shortly after, shooting antifreeze from the tailpipe.:lol3

    Eh...they make Rislone also, the only "miracle in a can" my grandpa believed in. He probably saw lots of miracles....or not:wink: in his long career as a mechanic going back to 1928.:clap
    #51
  12. LakeAbilene

    LakeAbilene n00b

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    Every GM I owned shot antifreeze from the tailpipe. I thought they were designed to do that!
    #52
  13. troidus

    troidus Long timer

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    I've seen it only twice, neither time on one of mine. One was a late-60s Pontiac 400 on which the block cracked in the lifter valley just below the deck on both sides, and the other was on a '75 Chevy 350 that got a split between the intake and exhaust valves on #5. That one ended up with a badly bent rod.
    #53
  14. H96669

    H96669 A proud pragmatist.

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    :roflNo and my dad was a GM dealer, sure wasn't a common problem back then. Maybe that they rusted into oblivion before that happened...:rofl Better out the tailpipe anyway than the compression pressurizing the cooling system. Not good loosing the heat when it overflows in cold climates.:lol3

    But them black V-8s from the 80's, sure did not measure up to the earlier ones.I think they were made in Mexico.:wink: But I mostly drove and abused 4 Bolt mains, red ones and blue ones!:lol3
    #54
  15. D.T.

    D.T. Difficult but useful

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    Update: I went shopping for a vehicle on Saturday and a dude on Craigslist seemed really cool. Until I called on Saturday. He hmmed and haaaad and said call later. I stopped at some used car dealers and you can't get much for under $3 grand.

    So I said F it and decided to try and tackle it in my driveway on Sunday morning. Temps were up around 32 degrees so that helped. Dropped the steering column with 4 nuts and all the F'n screws around the dash and it tilted back nicely. There is ENOUGH room to remove the core cover and core itself with out removing the big F'n mess of a dash. :clap So I got it shoehorned in. Took me about 5 hours before the rain sleet hit.

    $38 bucks for a heater core and it's done. I had to cut back the heater hose 2" because it was leaking at the motor. Went and spent another $21 on a new hose today. Going to put that in tomorrow.

    Anybody have any ideers on how to flush the cooling system at home?
    #55
  16. Benesesso

    Benesesso Long timer

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    What did the old antifreeze look like? Any rust? Color? The answers can make a difference to how you proceed.
    #56
  17. D.T.

    D.T. Difficult but useful

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    There is a little bit of sludge (dexcrap orange) in the system. I usually remove the reservoir and dump it down the toilet. Then rinse all the sludge out and flush it (going to get some crap about this). I put some prestone cleaner in the reservoir last year.

    If I had to I can get a 5 or 15 gallon plastic container and put the spent coolant in there, but where would I bring it to?

    Oh and BTW, to the dude at first gear garage that told me I needed to evacuate the air conditioning system...:fyyff
    #57
  18. villageidiot

    villageidiot Long timer

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    i would (while changing heater hose) unhook the old hose from the engine, and hook one end of the new hose to the engine, hook a garden hose (if not frozen solid) to an open end of the hose, and turn it on flush it thru until clean water comes out the open end of hose.

    then unhook lower radiator hose and drain system completely, and fill with fresh cooolant/anti corrosion/water mix
    #58
  19. Benesesso

    Benesesso Long timer

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    I won't run the orange stuff. If you want to continue with it your flush will be easier. Me, I'd flush it all out using several changes with tap water, then refill with 50/50 green AF. You might even try adding some Bars Leak.
    #59
  20. H96669

    H96669 A proud pragmatist.

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    The engine probably has a dedicated coolant drain plug, or two. You should open them up. Hard to get the crud from the bottom of the water jackets out if not doing so. I have opened a few of them where nothing came out until I pushed at the crud with a punch or pick.

    We even had an adapter at the shop way back then to flush from the drain plugs. Hoses have to be removed so you don't send the crap to the radiator.
    #60