Results 1 to 6 of 6

Thread: Knock

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Nov 2017
    Location
    Suffolk, VA
    Posts
    3

    Post Knock

    Hi: I'm a new guy on the block. We (my son and I) just purchased a "new to us" 1998 GMC 2500 6.5 turbo diesel originally owned and operated by VDOT. We seem to be the 3rd owners since it was state owned. We bought it at a bargain price because of the loud knock and the code message that No. 6 cylinder was not working. Thought it might be an injector but with all new injectors have now been able to hear a very loud knock in No. 6. The body of the truck is in excellent shape for it's year, but the engine has 396,752 miles. Should we tear it down and rebuild it or just worry about the No. 6 cylinder?

  2. #2
    Join Date
    Apr 2001
    Location
    CA
    Posts
    13,573

    Arrow

    Welcome aboard!

    If you've eliminated the injectors, I suspect a repower will be in order. A rebuild or replace will depend on what you find on disassembly. With that many miles and a very loud knock, the likelihood of broken crank, main or some other more serious issue is much higher. You've already dealt with the possible #6 fix about as much as you can, so anything further will be an overhaul.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  3. #3
    Join Date
    Nov 2017
    Location
    Suffolk, VA
    Posts
    3

    Post Knock

    Thanks for your thoughts on the situation. You answered our concerns with a confirmation for pulling the engine and checking out the insides. We sorta thought that was gonna be our "need to do." We have the garage, the chain falls and the engine stand. Appreciate your experience. We shall keep on learning and post the outcome.

  4. #4
    Join Date
    Jan 2001
    Location
    Knoxville,Tennessee
    Posts
    2,639

    Default

    Hope you have a stout engine stand. These 6.5s aren't light.
    "The Constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government."
    -Patrick Henry


    A5150nut
    2006 K3500 D/A
    94 6.5 4x4 5spd Sold

  5. #5
    Join Date
    Sep 2003
    Location
    Feeniks, Aridzona
    Posts
    1,114

    Default

    Quote Originally Posted by a5150nut View Post
    Hope you have a stout engine stand. These 6.5s aren't light.
    Bought a heavy duty unit from Harbor Freight. I scrapped all the cheap hardware and used grade 5 stuff everywhere. Works nicely.
    1987 Jeep Grand Wagoneer...new 6.5 in process...diamond block, 18:1's, other goodies...


  6. #6
    Join Date
    Nov 2017
    Location
    Suffolk, VA
    Posts
    3

    Default Knock

    Great Idea. Will do the same. Our stand has seen a few engines but they were not 6.5's. Thanks.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •