Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Thorley header problem

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by chev4life, Jan 7, 2006.

  1. chev4life

    chev4life 1/2 ton status

    Joined:
    Jun 21, 2001
    Posts:
    416
    Likes Received:
    0
    Location:
    San Jose, CA
    Alright guys...I have given up and need some help. I put thorley tri-y's on my 87 K5 about 8 months ago and I cannot get ride of this stupid exhaust leak:mad: I have welded the y-pipe slip fitting and replaced all the gaskets w/ crush gaskets and it wont go away. I cant really hear it when I rev the engine out of gear but in gear its super loud (almost as loud as my magnaflow)...its a whooshing sound w/ some minor soft ticking. Also...the main colector flange bangs my frame right at the tranny crossmember...any ideas on this?
    One of the things I was thinking was maybe my egr is leaking...has anyone had this problem? Any ideas you guys can give would be awesome.
    THANKS!:bow:
     
  2. chev4life

    chev4life 1/2 ton status

    Joined:
    Jun 21, 2001
    Posts:
    416
    Likes Received:
    0
    Location:
    San Jose, CA
    Someone has to have a little insight here....right?
     
  3. ryoken

    ryoken Puppy Fabricator Premium Member GMOTM Winner

    Joined:
    Jun 13, 2003
    Posts:
    29,623
    Likes Received:
    1,379
    Location:
    Jersey Shore
    can you pinpoint it somewhat? at the head? collector?
     
  4. ryoken

    ryoken Puppy Fabricator Premium Member GMOTM Winner

    Joined:
    Jun 13, 2003
    Posts:
    29,623
    Likes Received:
    1,379
    Location:
    Jersey Shore
    can you pinpoint it somewhat? at the head? collector?
     
  5. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    if you have the smog tubes or o2 sensor in the header, be sure neither of them are loose. If you used those fiber gaskets that came with em, might try a set of copper gaskets. Friend of mine had a bad problem with a header leak (non thorleys) and couldnt get rid of it. Put on copper gaskets at the head and the collector, no more leaks. I put coppers on mine the day I put my headers on.
     
  6. chev4life

    chev4life 1/2 ton status

    Joined:
    Jun 21, 2001
    Posts:
    416
    Likes Received:
    0
    Location:
    San Jose, CA
    I am using the super thick crush gaskets on all flanges. Only used the ones that came with them for a month and tried something different.
    I cant pinpoint it...thats the problem...I cant really hear it near any of the collectors and there is too much other engine noise when I am trying to listen next to the heads. It really only shows under load which is my biggest problem.
     
  7. divorced

    divorced 3/4 ton status

    Joined:
    Jul 20, 2004
    Posts:
    5,115
    Likes Received:
    0
    Location:
    .
    I use stock exhaust manifold gaskets and never have any problems. And here is how I fix collector leaks, they NEVER leak...



    [​IMG]
     
  8. Leadfoot

    Leadfoot 1/2 ton status Premium Member

    Joined:
    Nov 28, 2000
    Posts:
    3,112
    Likes Received:
    1
    Location:
    Western Massachusetts
    Have someone else get in the vehicle, set the parking brake, press the brake pedal and put into gear. Hold the throttle enough to put a load on it without moving and it should make it easier for you to pinpoint the leak (that is what I used to do). Of course common sense and safety should be used.

    EDIT: I have not had much luck with copper gaskets (especially the o-ringed kind). The one's that have worked best for ME are Percy's aluminum. FWIW
     

Share This Page