Hissing sound after turning engine off

Discussion in 'High Tech Retrofits' started by 75Maro, May 5, 2019.

  1. supwicha

    supwicha Veteran Member

    Messages:
    182
    Likes Received:
    14
    Joined:
    Feb 23, 2014
    Location:
    Victorville, CA
    That appears to be the coolant hose for the TB heat, not vacuum.
     
  2. supwicha

    supwicha Veteran Member

    Messages:
    182
    Likes Received:
    14
    Joined:
    Feb 23, 2014
    Location:
    Victorville, CA
    You photos show the brake booster vacuum circuit, not the PCV circuit from what I can see. I'm looking for a hose connection that goes from the intake to the PCV either at the valve cover or the other entry to the block. Do you have that?
     
  3. 75Maro

    75Maro Veteran Member

    Messages:
    420
    Likes Received:
    17
    Joined:
    Mar 31, 2008
    Location:
    Dallas,Tx
    You are correct. I just googled ls1 PCV setup and realized I have the pass side valve cover connected to the intake (wrong). I need to reroute it to the TB nipple on the same side (pass side).

    The small red breather is connected to the driver side valve cover and there is no routing to the intake (wrong) I also see from a google search that this isn’t correct either. I need to reroute this to the intake.
     
  4. 75Maro

    75Maro Veteran Member

    Messages:
    420
    Likes Received:
    17
    Joined:
    Mar 31, 2008
    Location:
    Dallas,Tx
    I will post updated pics in the morning thanks for your help so far guys.
     
  5. badazz81z28

    badazz81z28 Veteran Member

    Messages:
    16,371
    Likes Received:
    404
    Joined:
    May 4, 2001
    Location:
    Las Vegas, NV
    5342F80D-16BA-42A0-89FD-451CAAC4AA42.png Yup, I think you’re creating vacuum in the PVC while it’s running and when you shut it off it releases. The the valve cover should be drawing in fresh air that’s metered. Ie valve cover hose connected to the throttle body. Where the crank case air exits (driver valve cover) connects to the intake manifold to be burned. Since your fuel injected, you shouldn’t have any unmetered air entering the engine. Get rid of the red filter and route that to the intake manifold. Don’t forget the check valve.
     
    Last edited: May 21, 2019
  6. 75Maro

    75Maro Veteran Member

    Messages:
    420
    Likes Received:
    17
    Joined:
    Mar 31, 2008
    Location:
    Dallas,Tx
    This is great info.
    Thanks
    I can’t make out the words in the picture. What are the comments on the blue line.
     
  7. dave@ztech

    dave@ztech Veteran Member Lifetime Gold Member

    Messages:
    3,320
    Likes Received:
    686
    Joined:
    Mar 27, 2016
    Location:
    NY
    one says clean side the other says dirty side
     
  8. badazz81z28

    badazz81z28 Veteran Member

    Messages:
    16,371
    Likes Received:
    404
    Joined:
    May 4, 2001
    Location:
    Las Vegas, NV
    Green is clean fresh air from the TB, the blue is dirty coming out of the engine to enter the intake manifold to be burned. The check valve is so air can only be pulled into the intake and not out of it.
     
  9. 75Maro

    75Maro Veteran Member

    Messages:
    420
    Likes Received:
    17
    Joined:
    Mar 31, 2008
    Location:
    Dallas,Tx
    Any suggestions on the check valve.
     
  10. 75Maro

    75Maro Veteran Member

    Messages:
    420
    Likes Received:
    17
    Joined:
    Mar 31, 2008
    Location:
    Dallas,Tx
    86ED0DF7-5AD2-4D9D-8DD7-CCF3A8352496.jpeg 1D14DE05-CB47-4F7D-9318-22D7979BEED9.jpeg 04E98951-21D0-406A-863F-F05D2047F2CE.jpeg Update: the hissing sound now last about .5 second after shut off. Thanks for all the help. Only thing missing now is the check valve.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.