Jump to content

5.3 A8 noticeable shudder when in AFM Mode


Recommended Posts

On 5/17/2019 at 11:25 PM, HondaHawkGT said:

DFM is 10 times smoother than AFM was in my 2014, which itself was supposedly a huge improvement over AFM in the GMT900's. I'm okay with DFM considering I average over 24 MPG on long highway runs at 60-65 MPH. It's very difficult to notice unless I focus on it very carefully.

Dang, you got a 2019 now?  Nice,nice!  How is that combo 5.3L with DFM and 8speed?  Pretty good I bet?  I drove one and it was very good compared to my 2016 5.3L 8speed?  I had decided that it was good enough to not even really warrant a 6.2L in my future?

Link to comment
Share on other sites

19 minutes ago, mookdoc6 said:

Dang, you got a 2019 now?  Nice,nice!  How is that combo 5.3L with DFM and 8speed?  Pretty good I bet?  I drove one and it was very good compared to my 2016 5.3L 8speed?  I had decided that it was good enough to not even really warrant a 6.2L in my future?

So far it's been great. VERY smooth powertrain. I love the new sport mode. I like that I can switch to sport and the truck feels faster than my tuned 2014 did. When I'm just cruising the highway, if I leave it in normal mode with the cruise set I'll get 24-25 MPG highway without trying. Plus DFM is barely noticeable. I miss a few things with my 2014 but the improvements with the 2019's were big enough to get me to trade. 

 

 

 

Link to comment
Share on other sites

On ‎6‎/‎14‎/‎2019 at 4:48 PM, HondaHawkGT said:

I would have the dealer check it over if it's as bad as you're saying it is.

Hasn't thrown a code yet, and shudder is consistent but not worse.  Dealer visit will come soon, inquire about the A8 flush and see if it applies to the 19s.

Link to comment
Share on other sites

  • 4 weeks later...

I said earlier I was having the same problem and it was annoying.  Now, at 2,000 miles my truck is much better about this shudder/vibration.  I almost don't feel it anymore.  Hope your issue is resolved if not already.

Edited by ndking1126
Link to comment
Share on other sites

3 hours ago, ndking1126 said:

I said earlier I was having the same problem and it was annoying.  Now, at 2,000 miles my truck is much better about this shudder/vibration.  I almost don't feel it anymore.  Hope your issue is resolved if not already.

Could have been bad fuel in your case. Bad fuel had a tendency to make AFM run a little rougher IMO.

Link to comment
Share on other sites

  • 3 months later...

I have a 2019 Silverado 4x4 crew cab, and when the DFM kicks in at 65 mph, the whole truck vibrates. I can't have that nonsense going on because it's noisy, distracting and anything not nailed down, rattles. It goes away when I drop it into manual 7th gear, or if I raise the speed to 75 mph. Why in the heck would a manufacturer implement this technology into a pickup truck to begin with? I bought the truck for its towing power, not for fuel economy. If I wanted fuel economy, I'd buy a Toyota CAR.

  • Like 1
Link to comment
Share on other sites

7 hours ago, Doug in East Bethany said:

I have a 2019 Silverado 4x4 crew cab, and when the DFM kicks in at 65 mph, the whole truck vibrates. I can't have that nonsense going on because it's noisy, distracting and anything not nailed down, rattles. It goes away when I drop it into manual 7th gear, or if I raise the speed to 75 mph. Why in the heck would a manufacturer implement this technology into a pickup truck to begin with? I bought the truck for its towing power, not for fuel economy. If I wanted fuel economy, I'd buy a Toyota CAR.

It sounds like you may have the 8 speed trans shudder. What trans and engine do you have? Custom,LT,LTZ,HC?

Edited by 2016 Sierra Owner
added ?
Link to comment
Share on other sites

On 5/27/2019 at 8:43 AM, NW-99SS said:

This is what makes me thing something is wrong with my 2019 work truck.  Although I am comparing a '19 - 5.3 to a '17 - 6.2

 

My '17 Denali is smooth and nearly imperceptible, I can tell every time the DFM kicks in on the 2019.

Same thing on my 19 6.2, 17 6.2 was perfect and better mpg

Link to comment
Share on other sites

On 11/10/2019 at 8:34 PM, Jeb1300 said:

Same thing on my 19 6.2, 17 6.2 was perfect and better mpg

My 19 work truck is still shuddering and now the 1-2 shift is getting worse.  Nothing catastrophic yet, and no codes, was just at the dealer for a service with no reports.  See how the winter goes...

 

My 17 is much smoother and also gets better MPG with the 6.2 than my 19 with the 5.3.

Link to comment
Share on other sites

On 11/13/2019 at 10:01 AM, NW-99SS said:

My 19 work truck is still shuddering and now the 1-2 shift is getting worse.  Nothing catastrophic yet, and no codes, was just at the dealer for a service with no reports.  See how the winter goes...

 

My 17 is much smoother and also gets better MPG with the 6.2 than my 19 with the 5.3.

Just got ours back from dealer, everything normal. The 19 is a really disappointing truck compared to the our 17, should have kept it.

Link to comment
Share on other sites

On 11/16/2019 at 6:47 PM, Jeb1300 said:

Just got ours back from dealer, everything normal. The 19 is a really disappointing truck compared to the our 17, should have kept it.

Fortunately, I can keep my personal truck and get to see how the new ones perform with my work truck's.  Won't be selling my 17 anytime soon.

Link to comment
Share on other sites

After more driving I am convinced it is the 6.2DFM and the new 10 speed. With 2000 miles now this truck just does not coast or free wheel at all like the 2017 6.2 and 8 speed. With the 8 speed you get to cruising speed and back of the throttle and use low rpms and torque, can get anywhere from 22-28mpg highway and just a pleasure to drive. If you try the same thing on the 2019 with the 10 speed as soon as you let back on the throttle it drops cylinders and feels like the brakes are dragging. To maintain speed you have to keep your foot on it all the time at the expense of 2-4mpg. Who at gm does such a lousy job at programming these things? I would take my 8 speed back in a heart beat. The 10 speed goes like snot off the line in sport mode, beyond that I find no redeeming qualities. Baffling how they can go so far backwards with a new model.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    245.8k
    Total Topics
    2.6m
    Total Posts
  • Member Statistics

    333,236
    Total Members
    8,960
    Most Online
    Lightning123
    Newest Member
    Lightning123
    Joined
  • Who's Online   2 Members, 0 Anonymous, 609 Guests (See full list)




×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.