Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Sir Koscoe, Feb 19, 2013.

  1. Sir Koscoe

    Sir Koscoe New Member

    Tonight my heater smells like antifreeze and now it blows out a white mist. The mist smells and leaves a film on the windows that will not come off easily. It will not defrost the window so now I can't see anything. This is unsafe to drive and our van is broken right now so it can not be driven. I need help please!!!!!!!!!!
  2. stchman

    stchman New Member

    Sounds like you have a leaking heater core.

    What year is your Silverado?
  3. Sir Koscoe

    Sir Koscoe New Member

    it's a 99. after Googling for hours last night and talking to a few people today, it does sound like the heater core crapped itself. Where is it located? Under the dash?

    - - - Updated - - -

    Is $350-$450 a good price on having the core changed out by my local machanic?

    99'HEARTBEAT Moderator Staff Member

    Yes.......the Heater Core is located under the dash, here's a Video, on removed the old Heater Core, and installing a New One,
  5. Sir Koscoe

    Sir Koscoe New Member

    I watched that already. I'm just going to have it done. Going to bypass the core so I can run the truck without it leaking.

    99'HEARTBEAT Moderator Staff Member

    Sorry, you didn't mentioned that you had Viewed that Video.....:)
  7. Sir Koscoe

    Sir Koscoe New Member

    I ddin't watch it until this morning at work. It appears to labor intensive for me to attempt. I hate spending that kind of money on labor since the part is only $61. I would rather it be done right then me screw something up in the process.
  8. j cat

    j cat Active Member

    with the dash to be removed to do this I would say 400.oo is a good price. bypass the heater core by connecting the 2 hoses together. they have fittings at the auto part stores for this.

    what type coolant do you use ? dexcool gm approved or compatibles coolant ?
  9. trentkoger

    trentkoger New Member

    Sounds like you need to make friends with a good mechanic that always helps out on the price lol.
  10. Sir Koscoe

    Sir Koscoe New Member

    The truck has dex in it now, but I always have the dex flushed and replaced by green.

    If you are looking at the engine, the coolant line on the left going into the firewall can be disconnected and re-connected back into the block by disconnecting the line on the right from the block, correct?
  11. j cat

    j cat Active Member

    you can do it that way what matters is the LOOP must be maintained. this is so output of the water pump goes back into the pump suction input. they have the connector to do this bypass by just removing the hoses at the heater core then using the fitting connect the 2 hoses together.

    post back why its leaking corroded or cracked plastic
  12. Sir Koscoe

    Sir Koscoe New Member

    is it safe to do it that way?
  13. Conlan Rose

    Conlan Rose Super Moderator

    Yup perfeclly safe the way [MENTION=39185]j cat[/MENTION] described it. This is how the heater works normally when the heat is set to max cold it just stops sending it to the heater core.
  14. Sir Koscoe

    Sir Koscoe New Member

    i meant it i were to do it the way i described?
  15. Conlan Rose

    Conlan Rose Super Moderator

    It will put stress on the water pump.
  16. TRPLXL2

    TRPLXL2 New Member

    That is a great price on labor for that job, I know I wouldn't do it for that lol!! Too much that could be messed up under that dash, electrical and clips being broken and so on.
  17. j cat

    j cat Active Member

    perhaps I did not understand you correctly. however when you do this bypass "the flow must not be stopped or restricted".

    is that clear ? do not plug up any hoses or stop any flow out of / into the water pump.

    most connect the two hoses together or put a hose on the water pump so it connects the two pump fittings together to allow the coolant flow.
  18. D4gw00d

    D4gw00d New Member

    I have replaced a heater core in a Grand Am and in a Volvo, but not in a full-sized truck/van. I will be replacing the squirrel cage fan in our 'burban as soon as the weather breaks.

    If you have this done it is a good time to consider anything else in the dash that is annoying/needs fixing.

    Any bulbs out? Crackling speakers? Rattling vents? Any hanging wires or poorly fit plastic components? Is your heater fan squealing or chirping?

    You really don't want to disassemble the dash and have a second go at this, so you may as well fix whatever annoying things are under there all at once.

    Having said that, most of what you will be taking apart or putting back together will be cosmetic or comfort stuff, so it isn't really all that complicated as long as you have a decent manual, and lay out the parts in such a way that you have no trouble finding what goes where when reassembly time comes.

    I know you plan on hiring this job out, but it really isn't complicated. You do need to be a contortionist and to be patient and organized. Oh, and to have lazer vision to figure out wher the jeebus clips end up.
  19. Sir Koscoe

    Sir Koscoe New Member

    i guess i mean to say loop from water pump to water pump bypassing the core with one hose. Are the hoses different sizes?
  20. stchman

    stchman New Member

    Why would you want normal green coolant, that stuff has to be changed every 30K miles or so. Dexcool can go up to 100K, but I've read that 75K miles is a good interval to change.

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