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  1. #1

    Default No Heat front or rear

    99 sub 5.7 no heat front or rear already replace t stat both heater cores , coolant refilled system still no heat i somtimes get heat out of the front then it goes away any ideas thanks

  2. #2

    Default

    Did you flush the system before the refill? And did you replace the other stuff because of no heat? It sounds like the radiator may be clogged.

    If it were me, I probably put the t-stat in backwards, but I'm learning to double check these things...

    Good luck,

    1999 Chevy K2500 Suburban 350
    K&N, reworked cai, Thrush cat-backs
    Vinyl, cranks, floor shift, and rear air!

  3. #3
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    If you've already replaced the T stat, & both heater cores then you're not getting any coolant flow. You aren't getting enough coolant flow to, or through your cores. Check both inlet & outlet hoses.
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
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  4. #4

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    it has a new engine all fittings and hoses are new line were cleanes out i flushed everything enginewas replaced due to brother severly overheating it rad was cloggged but cant get heat with every thing new ????

  5. #5
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    I still think this is a coolant flow problem. The hoses may be hooked in the wrong places out front since this was an engine replacement. Can you shoot us a couple pics so we can see where they go? Start at the firewall where the hoses come out & take pics all the way to where they go. I've seen mechs, & first timers just hook hoses where ever there is a bung even though it is not the correct place. If they have hooked your heater hoses to stagnent water sources this will not allow any flow & the only heat you would get to your heater cores, would be by capillary action, which would take forever to heat it up.

  6. #6

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    well i finally had time to play with my sub and it turns out the moran who did the engine for me put the hoses off the water pump in the wrong spots i guess thats what happens when you have someone else do work for me i was just to busy at work and home to get to it thanks for the help
    99 Sub
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    K&N cold arir kit
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  7. #7

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    Good to hear you got it figured out.

  8. #8
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    Quote Originally Posted by djssub View Post
    well i finally had time to play with my sub and it turns out the moran who did the engine for me put the hoses off the water pump in the wrong spots i guess thats what happens when you have someone else do work for me i was just to busy at work and home to get to it thanks for the help
    Well that certainly will do it. Switching the heater hoses on the engine is the same as switching them at the heater core, & there's a deflector plate inside the core that if the hoses are hooked backwards will almost stop the flow. Glad you got it sorted out.

  9. #9

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    it was dumber then that on the vortecs for the water pump has 2 outlets ont tyo the intake one for the heater the guy hooked it up pump to pump no wonder why i had no heat it also fxed the other problem i was having i should of cought that right away but thats what happens when a master tech has a coworker do it for him lol thanks for the input

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