Thread: Downshift/Acceleration Rattle

Results 1 to 4 of 4

Threaded View

stocker Downshift/Acceleration Rattle 07-26-2016, 02:05 PM
Scottydoggs Re: Downshift/Acceleration... 07-26-2016, 02:08 PM
stocker Re: Downshift/Acceleration... 07-26-2016, 04:24 PM
Scottydoggs Re: Downshift/Acceleration... 07-26-2016, 04:28 PM
Previous Post Previous Post   Next Post Next Post
  1. #1 Downshift/Acceleration Rattle 
    GTP Level Member
    Join Date
    Aug 2012
    Location
    st louis park, MN
    Posts
    616
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    Hi All,

    I've had this issue for quiet a while but had always chalked it up to the cat heat shield - until that flew off on the highway and the noise persists.

    It is very repeatable if I wait for the car to shift into 2nd then I get it to downshift into 1st. I'm pretty sure it happens from 3 to 2 as well its just not as easy to hear at higher speeds. It also happens sometimes if I bump the accelerator without a downshift but still accelerate moderately.

    It is a metallic, rhythmic rattle - it appears suddenly and seemingly fades over a second or two. In my mind, it seems to have something to do with the jarring off the engine/trans as the down shift occurs.

    It is especially noticeable it I am driving near walls, fences or concrete barriers as the sound is reflected back to me. It really sounds terrible and janky as hell.

    Please advise or share ideas ... thanks!

    EDIT: The rattle is probably about as fast as someone can sputter there lips if they are fed up with something. Bit slower maybe.
    Last edited by stocker; 07-26-2016 at 02:09 PM. Reason: rattle speed estimation
    2008 Grand Prix Base: Engine cover delete , flipped dogbone bushings, Transgo shift kit, Hayden 403 trans cooler,
    Quote Originally Posted by Yarbeau View Post
    we are all anal about our vehicles. Otherwise we would not be on an extinct platforms forum debating 3000 dollars cars!
    Reply With Quote  
     

Similar Threads

  1. Downshift Slip With WOT
    By wa04compg in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 14
    Last Post: 09-18-2013, 10:27 PM
  2. Slow downshift
    By jdkhunter in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 1
    Last Post: 07-26-2012, 09:59 PM
  3. Downshift???
    By TheNoob23 in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 12
    Last Post: 02-11-2011, 05:29 PM
  4. new pcm. hard downshift from 2nd to 1st at stops??
    By colindunn in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 15
    Last Post: 09-18-2010, 07:10 PM
  5. Downshift hesitation
    By rocket69GTP in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 0
    Last Post: 05-08-2010, 10:05 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •