Popping noise in the AC/heater box

Discussion in 'The Big Chill' started by jaye, Jul 22, 2022.

  1. jaye

    jaye Well-Known Member

    I have a 69 Skylark and it’s making popping noises on the passenger side heater box. I’ve had this issue for a couple years now, it doesn’t occur all the just occasionally. This morning while driving to work in traffic it starts popping, so I turn the heater on (it’s almost 90 degrees here)and it stopped? Any ideas or suggestions?
     
  2. 69WILD

    69WILD Ron

    Does it sound like a rattle? Does it change with blower speed? Doesn't matter if car is moving?
     
  3. jaye

    jaye Well-Known Member

    It’s popping, it doesn’t matter if the car is moving or not. This morning is the first time I turned the heat on while it was popping. I’m thinking maybe the vacuum diaphragm, I’ve never had one go out or had issues so I don’t know any symptoms it would produce.
     
  4. 69WILD

    69WILD Ron

    Ac car? If you get it to happen again you could unplug vacuum supply?
     
  5. Max Damage

    Max Damage I'm working on it!

    If it sounds like an electrical popping noise, it might be the blower resistor? Perhaps it's arcing? That is on the engine compartment side, but who knows?
     
  6. jaye

    jaye Well-Known Member

    It’s not electrical, it sounds like something maybe closing and keep popping back open again. If you hit the heater box with a screwdriver will come close to the sound it makes. If it does it when I get home I’ll unplug the vacuum and see what happens. It’s an A/C car however I took the evap out and A/C delete cover was installed
    Thanks for the replies fellows
    Jaye
     
  7. Max Damage

    Max Damage I'm working on it!

    Vacuum related air door slamming…
     
    philbquick and 12lives like this.

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