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AFM issues

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Old Oct 21, 2019 | 11:53 AM
  #1  
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Default AFM issues

Posting in here as I understand each engine has different AFM parameters etc. Just got back from a great 3K mile road trip to the Carolinas to do some twisties driving in my '16 Z. The car ran perfectly, especially when being pushed hard.

But on the highway, the AFM seems to ba acting up. Especially around 65mph, the car is constantly stumbling, shuddering, etc. It made the rattling noise from day one when coming in and out of V4, but the shuudering and stumbling is new as of this drive. Car now has 20K on it. Any ideas before I go to the dealer for the inevitable "seems to be running fine".
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Old Oct 21, 2019 | 12:03 PM
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Originally Posted by TTRotary
Posting in here as I understand each engine has different AFM parameters etc. Just got back from a great 3K mile road trip to the Carolinas to do some twisties driving in my '16 Z. The car ran perfectly, especially when being pushed hard.

But on the highway, the AFM seems to ba acting up. Especially around 65mph, the car is constantly stumbling, shuddering, etc. It made the rattling noise from day one when coming in and out of V4, but the shuudering and stumbling is new as of this drive. Car now has 20K on it. Any ideas before I go to the dealer for the inevitable "seems to be running fine".
I have only had my '16 A8 Z06 4K miles, since July and have never experienced any issues with AFM but I just learned last week reading the OM that in Manual AFM is disengaged and I almost always drive in manual so my AFM has probably only engaged a few times. I did just get the flush and fluid change for my A8 last week under warranty even though I had never experienced any shudder (I told my service tech it shuddered on me once), so if yours is an A8 that is an option. Good Luck.

Last edited by usrodeo4; Oct 21, 2019 at 12:05 PM.
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Old Oct 21, 2019 | 12:07 PM
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Sounds like another transmission woe to me. Get ready to go back and forth for fluid changes until you're fed up with the car and trade it on something else.
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Old Oct 21, 2019 | 01:29 PM
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This is definitely AFM related as it happens just as the V4 to V8 switch occurs. Although I can believe the shuddering is trans related. Two separate problems?
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Old Oct 21, 2019 | 02:03 PM
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Default Constructive Suggestion

To get rid of the V8/V4 mode all of the time and not have anything in your car get a DS hand held tuner (works well) or etc. Just remember to remove the tune if you take it to the dealer for service.

Why have trouble/PITA if you can avoid it in the first place?

Last edited by C7/Z06 Man; Oct 21, 2019 at 02:08 PM.
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Old Oct 21, 2019 | 02:07 PM
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Originally Posted by C7/Z06 Man
To get rid of the V8/V4 mode all of the time and not have anything in your car get a DS hand held tuner (works well) or etc. Just remember to remove the tune if you take it to the dealer for service.
Or just drive in Manual for the A8 or in Tour or Sport for the M7
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Old Oct 21, 2019 | 02:14 PM
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Originally Posted by usrodeo4
Or just drive in Manual for the A8 or in Tour or Sport for the M7
I prefer using "D" mode almost all the time street or strip, it does a better job (programing) from a performance standpoint and you don't even have to think about it.
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Old Oct 21, 2019 | 02:22 PM
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I'll try M as a workaround. Anybody know if there are issues with the AFM lifters or solenoid failing on the LT4?

Same type of question on the A8 ...
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Old Oct 21, 2019 | 02:36 PM
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Get the "Range" AFM disabler and avoid the issue. If nothing else, it will isolate the problem, i.e. whether you have an AFM problem or a trans. problem.
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Old Oct 21, 2019 | 02:51 PM
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Originally Posted by mikegaan
Get the "Range" AFM disabler and avoid the issue. If nothing else, it will isolate the problem, i.e. whether you have an AFM problem or a trans. problem.
Thanks but I'd really like to avoid getting into tuning, removing the tune, etc. Also have read the Range product is very hit or miss any may cause problems. Apparently, AFM programming is very different on each engine type and year.
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Old Oct 21, 2019 | 02:57 PM
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Somewhat true, but the hit or miss with the Range seems to depend on the version/update, e.g. buying through Amazon. Buying directly from the company guarantees the current version. Got mine some 6 months ago and have had no issues. No tuning required, just plug it in. Mine will go past 2 weeks without draining the battery. Never sat for longer periods, so can't verify beyond that.
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Old Oct 21, 2019 | 09:30 PM
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Originally Posted by mikegaan
Somewhat true, but the hit or miss with the Range seems to depend on the version/update, e.g. buying through Amazon. Buying directly from the company guarantees the current version. Got mine some 6 months ago and have had no issues. No tuning required, just plug it in. Mine will go past 2 weeks without draining the battery. Never sat for longer periods, so can't verify beyond that.
Thanks Mike. Like your avatar BTW. That's my favorite plane and one of my fave cars as well. I actually have a turbine RC model of the Eagle. It's a handful and a thrill to fly.
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Old Oct 22, 2019 | 08:33 AM
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Originally Posted by C7/Z06 Man
I prefer using "D" mode almost all the time street or strip, it does a better job (programing) from a performance standpoint and you don't even have to think about it.
Yeah I get that...if I am trying for a time or am racing someone I will use D for sure (I do like to use M on rolls to make sure I start in the gear I want then slide to D) but when I am just putting around town I like using M just for some involvement, and for the giggle producing rev matches on down shifts. Plus I removed fuse 42 so with the flaps always open, in D you get some odd droning at cruising speed when the AFM kicks in and out, which I hated so M fixes that too.
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