Advice Needed - Exhaust Manifold Leak

Mopar Exhaust Systems

  1. 1969VADart

    1969VADart FABO Gold Member FABO Gold Member

    Messages:
    2,363
    Likes Received:
    648
    Joined:
    Aug 19, 2013
    Location:
    Fredericksburg, VA
    Local Time:
    8:48 PM
    So as you can see from the pictures, the end stud on my exhaust manifold is leaking. The end is a threaded stud in the head that the nut should tighten down on. Unfortunately, the nut doesn't tighten because the stud spins. I am thinking it may be stripped in the head. I am trying not to talk myself into pulling the whole motor and doing a complete refresh (don't really want to go to all the trouble). I assume I could pull the manifold and re-thread the head or use Helicoil. However, I am not sure how to get the bad stud out. Also not that experienced with the Helicoil to know what I should be looking for. Would appreciate some advice on how to repair this.

    Exhaust Manifold 1.jpg

    Exhaust Manifold 2.jpg
     
  2. Northern Grit

    Northern Grit Active Member

    Messages:
    44
    Likes Received:
    36
    Joined:
    Jul 21, 2020
    Location:
    Michigan
    Local Time:
    8:48 PM
    Take out all your manifold bolts and if the stud that spins doesn't just pull out then turn it while tugging on the manifold at the same time, it should work it's way out. If it's spins because it's snaped off then you could pull it with pliers. Then when you can get an eyeball on the situation reassess from there.
     
    • Agree Agree x 1
    • 66fs

      66fs FABO Gold Member FABO Gold Member

      Messages:
      4,817
      Likes Received:
      1509
      Joined:
      Sep 9, 2009
      Location:
      Greenwood, South Carolina
      Local Time:
      8:48 PM
      There is coolant behind that stud. Heli-coils work as good or better than new. Use high temp RTV when you reinstall the stud.
       
      • Agree Agree x 1
      • toolmanmike

        toolmanmike FABO MODERATOR Staff Member FABO Gold Member

        Messages:
        50,524
        Likes Received:
        35542
        Joined:
        Jan 18, 2006
        Location:
        Iowa
        Local Time:
        7:48 PM
        All 4 corner exhaust studs screw into a water jacket. All 4 need sealer of some sort. Like 66fs suggested, high temp silicone works well. I have used liquid teflon as well although I don't know about it's temperature limits.
         
      • Syleng1

        Syleng1 Karma is real and Life is short... FABO Gold Member

        Messages:
        1,641
        Likes Received:
        1198
        Joined:
        Jul 5, 2005
        Location:
        North Franklin, CT
        Local Time:
        8:48 PM
        The other option is an uneven stud. So the side that screws into the head is one size larger. 3/8” and it is about 3/4” long then drops down to 5/16” with a 2” length. With the un threaded part it’s like 3” long. You can drill out the hole to retap a 3/8” stud. Places like Mc Masters or Granger have them.
        Just another option from helicoil. If you don’t like helicoils. I mean what’s not to like- they saved my butt a few times. Just make sure you get the length correct or you bottom out before the stud is all the way in.
         
        • Like Like x 1
        • RustyRatRod

          RustyRatRod Bla de blizhibliz de blatde blizi bla bla FABO Gold Member

          Messages:
          61,843
          Likes Received:
          34000
          Joined:
          Jun 7, 2010
          Location:
          Georgia
          Local Time:
          8:48 PM
          I think this is the option I would choose. The reason is because a helicoil there is tricky. Since it goes into water, you need sealant on both sides of the helicoil. You cannot do that on the outside of the helicoil. It needs thread locker to keep the helicoil in place. Thread locker is not a sealer and it might leak around the helicoil. If you tap it up to 3/8 and us a reduced stud as Syleng suggested, you won't have that worry.
           
        • Oldmanmopar

          Oldmanmopar Going left turning right FABO Gold Member

          Messages:
          8,435
          Likes Received:
          4613
          Joined:
          Jan 8, 2009
          Location:
          Danielsville Pa. 18038
          Local Time:
          8:48 PM
          Put a jam nut on a turn it out,. install a helicoil without removing the manifold. easy peasy. been done many times. Make sure you use a short helicoil and break the install tab off because the stud goes in deeper until it bottoms. You can take the core plug out in the head to get a look at it from the back side if it is a stud at the front of the motor.
           
        1. This site uses cookies to help personalize 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.