Thread: Car bucks/surges in 3rd gear under light load.

Results 1 to 11 of 11
  1. #1 Car bucks/surges in 3rd gear under light load. 
    SE Level Member
    Join Date
    Oct 2019
    Location
    s.k.
    Posts
    5
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Chats
    0
    Hi all. This is my first post on this forum and I hope you can help. Bought an '07 Grand Prix for my son for school and have noticed a bucking/surging with RPM oscillating around a few hundred revs when under light throttle on a slight upgrade. At first I thought it may be shudder from Torque Converter but can also happen when selector is in 3rd gear. Accelerating seems to cure it. Any thoughts will be appreciated. Thanks
    Reply With Quote  
     

  2. Advertisement




  3. #2 Re: Car bucks/surges in 3rd gear under light load. 
    GrandPrix Junkie
    Join Date
    Oct 2009
    Location
    St. Louis
    Posts
    4,222
    Thanks (Received)
    8
    Likes (Received)
    26
    Dislikes (Received)
    0
    Chats
    0
    Sounds like TCC apply issue--> TCC rpm oscillation
    Reply With Quote  
     

  4. #3 Re: Car bucks/surges in 3rd gear under light load. 
    SE Level Member
    Join Date
    Oct 2019
    Location
    s.k.
    Posts
    5
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Chats
    0
    Quote Originally Posted by FordMan77 View Post
    Sounds like TCC apply issue--> TCC rpm oscillation
    I appreciate the reply. Upon reading the info you gave me, I'm not sure if this answers the RPM fluctuation in 3rd gear as well. Does the TC try to engage when the gear selector is manually in 3rd gear?
    Reply With Quote  
     

  5. #4 Re: Car bucks/surges in 3rd gear under light load. 
    Turbo is the way to go. BillBoost37's Avatar
    Join Date
    Jul 2009
    Location
    W Spfld
    Posts
    26,576
    Thanks (Received)
    39
    Likes (Received)
    60
    Dislikes (Received)
    1
    Chats
    96870
    Sounds a bit like an ignition issue to me. Maybe coils, wires or plugs. Do you have anyway to look for misfires while it's doing it?
    I drink..so consider that when reading my posts.

    2010 Audi A6 Dual IC's
    Reply With Quote  
     

  6. #5 Re: Car bucks/surges in 3rd gear under light load. 
    SE Level Member
    Join Date
    Oct 2019
    Location
    s.k.
    Posts
    5
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Chats
    0
    Quote Originally Posted by BillBoost37 View Post
    Sounds a bit like an ignition issue to me. Maybe coils, wires or plugs. Do you have anyway to look for misfires while it's doing it?
    I have the Bluedriver OBD2, yet still playing with it. No codes present. I realise that there may be no codes present and live data would determine misfires if present. I have heard about TP Sensor going bad. I will try my best diagnosing the problem,It's getting cold here in Canada now but I will keep you posted with any updates. Again,thanks to all those who have replied.
    Reply With Quote  
     

  7. #6 Re: Car bucks/surges in 3rd gear under light load. 
    Donating Users bandook's Avatar
    Join Date
    Apr 2015
    Location
    Columbus, OH
    Posts
    1,591
    Thanks (Received)
    0
    Likes (Received)
    10
    Dislikes (Received)
    0
    Chats
    226


    3rd locks at under 44% throttle. These are stock 07 tables.
    Top Swapped 01 Imp
    VS (very small?) cam, SD Headers, 2.8" pulley, self ported everything, E85, AEM water/meth, Deka 60's, HPT tuned
    Reply With Quote  
     

  8. #7 Re: Car bucks/surges in 3rd gear under light load. 
    SE Level Member
    Join Date
    Oct 2019
    Location
    s.k.
    Posts
    5
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Chats
    0
    I am finding the Bluedriver OBD2 beyond my technical abilities at this time.Hooked up a regular plugin OBD2 scanner and under enhanced GM DTC codes found a P0703 (Brake Switch B input). Checked that brake lights worked and functioned correctly and they appear to at this time. Cleared code and will update if the code returns or I notice any changes. Thanks again guys on the inputs,I really appreciate any and all suggestions fired at me. "Billboost37"-have yet to check ignition system yet as Bluedriver doesn't have the ability to select misfires for the GrandPrix (or am I missing something),"Fordman77"-If gear selector is manually in 3rd,Torque Converter lockup should not occur-correct?
    Reply With Quote  
     

  9. #8 Re: Car bucks/surges in 3rd gear under light load. 
    Donating Users bandook's Avatar
    Join Date
    Apr 2015
    Location
    Columbus, OH
    Posts
    1,591
    Thanks (Received)
    0
    Likes (Received)
    10
    Dislikes (Received)
    0
    Chats
    226
    Correct me if I'm wrong, but there are no different tcc apply/release tables in the PCM for manual shifting. That's why i posted the images to give you an idea of the tcc control.
    Top Swapped 01 Imp
    VS (very small?) cam, SD Headers, 2.8" pulley, self ported everything, E85, AEM water/meth, Deka 60's, HPT tuned
    Reply With Quote  
     

  10. #9 Re: Car bucks/surges in 3rd gear under light load. 
    SE Level Member
    Join Date
    Oct 2019
    Location
    s.k.
    Posts
    5
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Chats
    0
    Thank you for the reply. Do I then assume if gear selector is in 3rd and NOT drive, then this buck/surge issue I'm having points to a problem other than the transmission? Going down the possible ignition,TB(throttle body) route I go if that's the case. I did do a quick visual inspection of the ignition system checking for any loose,damaged leads,coils. I did notice the leads were made by Delphi (labelled) Are they OE?
    Reply With Quote  
     

  11. #10 Re: Car bucks/surges in 3rd gear under light load. 
    Donating Users bandook's Avatar
    Join Date
    Apr 2015
    Location
    Columbus, OH
    Posts
    1,591
    Thanks (Received)
    0
    Likes (Received)
    10
    Dislikes (Received)
    0
    Chats
    226
    I think the thing is that you would probably not see 3rd lock in manual without really trying. Try driving constant at say 30mph with as little throttle as necessary to lock the converter. Hold the speed steady and see if it surges.

    Like Bill said, scanning for misfires would help. If you can't scan for that, can you scan sensor 1 O2? You might see it acting up, maybe averaging higher like around .7-.800 if it's misfiring? That's just a guess. But there should be a way for your scanner to see misfires.
    Top Swapped 01 Imp
    VS (very small?) cam, SD Headers, 2.8" pulley, self ported everything, E85, AEM water/meth, Deka 60's, HPT tuned
    Reply With Quote  
     

  12. #11 Re: Car bucks/surges in 3rd gear under light load. 
    GrandPrix Junkie
    Join Date
    Oct 2009
    Location
    St. Louis
    Posts
    4,222
    Thanks (Received)
    8
    Likes (Received)
    26
    Dislikes (Received)
    0
    Chats
    0
    What's the mileage on the car? Have you pulled any of the plugs and checked to see condition? The wires being labeled as Delphi could be originals or someone just replaced them with OEM ones. FWIW just get the cheapest set of wires and they'll work just fine no need to spend the extra $$ on OEM stuff.

    I'm not one to throw parts at an issue but usually the first thing I do on a used car is replace the plugs/wires, remove and clean the TB, clean the MAF and install a new air filter. This ensures I have a good start point and maint. history on the car. And when you replace the wires get rid of the metal shields on the plug end if it has them. Not needed and can cause issues. Been running both my 3.8's like this for well over 100K miles and not once had an issue related to removing them.

    IIRC, the TC should unlock when you hit the brake pedal so when it starts bucking don't let off the gas just use your left foot and lightly press the brake pedal and see if the bucking stops.
    Reply With Quote  
     

  13. Likes Gingershrek liked this post
  14. Advertisement




Similar Threads

  1. RPM'S Flutter between 1700-2400 under load in 3rd-4th gear.
    By jdebus97 in forum General Grand Prix Discussion
    Replies: 7
    Last Post: 03-15-2017, 02:41 PM
  2. how to access light for ashtray and gear shift selector
    By 02 Black GTP in forum General Tech Discussion
    Replies: 2
    Last Post: 06-21-2016, 09:34 PM
  3. Fixing a dead miss on light load
    By carnut in forum 3.4L V6 (LQ1) DOHC
    Replies: 6
    Last Post: 06-02-2014, 10:10 PM
  4. Transmission shutters from first to sencond gear during light acceleration
    By jsingh0072007 in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 7
    Last Post: 05-30-2012, 09:28 AM
  5. Sometimes my Car surges when light throttle
    By 99GPGTP in forum 1997-2007 4 speed Automatic (4T65E) (4T65E-HD)
    Replies: 4
    Last Post: 05-11-2010, 08:54 AM
Tags for this Thread

View Tag Cloud

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
  •