Revs not dropping down in a linear way

[GT350/BT55]

I have a 2017 MY purch Aug 2016, with about 7500 miles.
So far so good, one AC repair, some other minor stuff.

I noticed something this year on my second drive after winter storage.
I drove about 160 miles this weekend, up and down the parkway to the shore.

On the way down I "thought" I noticed the revs dropping in a different way
when I put in the clutch at 4-5 thou RPM, it was like it drop a few hundred
RPM, and then stayed there of a few sec before continuing to drop down.

I know you don't normally go from say 4-5 and stop in between to watch the revs drop.
But since it did seem to "hang up" abnormally I tried it a few times and it did the
same thing.

I have a few vehicles, motorcycles, EVs etc., so maybe it is something it did before
but my 60 Y.O. brain is having memory issues. I just don't remember it doing this.
Maybe it does hang for a second between shifts so it does not drop too much.
Is there a throttle matching function in the in the mapping or something?

I just want to here what you guys say before I go to a dealer who tells me
"could not recreate situation" or something along those lines.

Car is a beast, still a lot of fun.

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[jvandy50]

do you know if it was tuned by previous owner? my lund tune did this at first, one revision and it was gone. called it "rev hang"...this might not be your issue. but a place to start nonetheless

 

[GT350/BT55]

do you know if it was tuned by previous owner? my lund tune did this at first, one revision and it was gone. called it "rev hang"...this might not be your issue. but a place to start nonetheless

No, it was mine from the get go. Nothing done to engine.

 

[jvandy50]

No, it was mine from the get go. Nothing done to engine.

i misread...i thought you bought it with 7500mi on it...carry on lol...i never had that issue until tuning.

 

[raiderjatt02]

Does it hesitate and surge at cruising speeds in 5th and 6th gear? Does your Cruise Control work? Could be due to this TSB.

https://www.mustang6g.com/forums/threads/tsb-19-2135-surge-or-hesitation.126435/

 

[GT350/BT55]

Does it hesitate and surge at cruising speeds in 5th and 6th gear? Does your Cruise Control work? Could be due to this TSB.

https://www.mustang6g.com/forums/threads/tsb-19-2135-surge-or-hesitation.126435/

Not sure if that would have anything to do with this issue.
I was not using cruise control at all. ( I don't think I ever have )

It's just this weird hang up or "pause" for a second when you press the clutch in.
Usually the revs will lust drop down without a pause, now its lie they drop off of a few hundred RPM, sit there for a second, and then continue down.

I guess I just have to run it by Ford and see what they say.

 

[Lilmags500]

Not sure if that would have anything to do with this issue.
I was not using cruise control at all. ( I don't think I ever have )

It's just this weird hang up or "pause" for a second when you press the clutch in.
Usually the revs will lust drop down without a pause, now its lie they drop off of a few hundred RPM, sit there for a second, and then continue down.

I guess I just have to run it by Ford and see what they say.

I too have been noticing some erratic but mild rpm // on the gas // off the gas quirkiness . My buddy is a Ford Master Tech , he said the 5.2
motors have inherent "minds of their own" and has trouble shot these symptoms before generally with no real issue found . He told me to
quit worrying about everything and drive it . He also said he doesn't want to hear another word from me until a check engine light
appears or the car wont go .... LOL .

 

[GT350/BT55]

I too have been noticing some erratic but mild rpm // on the gas // off the gas quirkiness . My buddy is a Ford Master Tech , he said the 5.2
motors have inherent "minds of their own" and has trouble shot these symptoms before generally with no real issue found . He told me to
quit worrying about everything and drive it . He also said he doesn't want to hear another word from me until a check engine light
appears or the car wont go .... LOL .

LOL that's pretty funny, but about what you would expect.
I guess I will just drive it more and see how it goes.

 

[Lilmags500]

LOL that's pretty funny, but about what you would expect.
I guess I will just drive it more and see how it goes.

Im willing to bet its fine , guys here have complained about lights on , on the dash and strange things happening only
to find once they cycled the ignition off and on again the issue was resolved .... GREMLINS !

 

[trevman2]

Can you post a video of what you are seeing? That might help diagnose or some others can try the same thing to see if the results are different.

 

[OppoLock]

My GT does this. Was hoping it wouldn't affect GT350s since I have one on the way.

It's most likely rev hang and not an abnormal characteristic. When shifting up from one gear to the next, if I press the clutch in--say from 4th to 5th--and keep it pressed, the revs will drop to exactly where they need to be at the given speed for a smooth 5th gear engagement, hang for a second, then continue to drop.

In other words, it allows a seamless engagement of the clutch without having to time the engine and wheel speeds when letting off the clutch. I'm not a fan of it because the initial drop is like a slow float, then a pause, then a normal rate of drop.

Tunes can eliminate this characteristic.

 

[TDC]

I had a rev hang issue in the higher gears at the same time as intermittent cruise control function and slight engine surge in 5th and 6th gear. Issues were fixed after the dealer replaced the transmission output sensor and the pedal sensors/switches.

 

[Lilmags500]

I had a rev hang issue in the higher gears at the same time as intermittent cruise control function and slight engine surge in 5th and 6th gear. Issues were fixed after the dealer replaced the transmission output sensor and the pedal sensors/switches.

Was a check engine or wrench light on ? A faulty speed sensor or OSS will more then likely trip a code ....

 

[raiderjatt02]

No check engine light but my car only does the rev hang thing when it's also doing the 5th/6th gear surge thing. It only happens after a hard pull in 1st --> 2nd --> 3rd. Then I can "fix" it by doing a medium pull in 4th gear to about 5k. I believe it's because of the output shaft but haven't taken mine in to the dealership yet.

 

[Byronj]

Our cars

Does it hesitate and surge at cruising speeds in 5th and 6th gear? Does your Cruise Control work? Could be due to this TSB.

https://www.mustang6g.com/forums/threads/tsb-19-2135-surge-or-hesitation.126435/

have cruise control? Haha. I’ll be at TH on Sunday. I couldn’t get in on Monday

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