02 Mustang GT Flat Spots?

[Cerwindel]

02 Mustang GT Flat Spots?! Help

Hey guys,

Having some trouble with my 2002 GT Auto Trans, under hard acceleration its fine through 1st gear, then when it kicks into 2nd, under full throttle, it feels like its a flat spot at 4000ish rpms, its like the car is still accelerating however it almost feels like the transmission is slipping. This continues through most of the gears at roughly 4000ish rpm?

I have a 75,000 Mile warranty Bumper to Bumper. I took it in and first they couldent find anything wrong.. Then I took the tech, and then hes like " wow there is a flat spot". So it stayed for 4 days, while they tried to look for a TSB. Then after 5 full days, they call me back and tell me " This is a design charastic of the vehicle, all the 2002's do that, we have another one here and it does the same thing, its totally normal..

So, how is a slipping / flatspot @ 4,000 rpm normal? Im thinking about taking it to another dealership to see what they can do? Suggestions ?

 

[mustang70]

Second opinions are always a good thing. You might want to check the tranny fluid. If it's slipping the fluid might smell burnt or be darker then it should be.

 

[Cerwindel]

Second opinions are always a good thing. You might want to check the tranny fluid. If it's slipping the fluid might smell burnt or be darker then it should be.

yeah the tranny fluid was replaced and it still does it.. Anyone else with a 2002 relate to this issue ?

 

[auto02]

same here,my 02 auto sometimes feels as though it is surging under wot in 2nd gear.

 

[Cerwindel]

same here,my 02 auto sometimes feels as though it is surging under wot in 2nd gear.

yeah is it like, WOT then kick to 2nd, then rite around 4k RPM its either flat, or surge, or Slip ... But it clears up by 5k and moves on...

So, Im ruling out Slip, because MPH pickup is not slowing.. Im ruling out tirespin, because id feel it, surging might be more precise.. Flat spot, mabye mabye not, im not seeing the detonation problems with a flat spot.. See, If i bring it in and get a tranny swap.. Will it fix it.. hrm..
\

 

[YtnGT]

Yup..

Yea I have that exact same issue @ 4K rpm. It is not the trans slipping it is a flat spot in the power curve. My predator tune is causing the flat spot issue. I use the factory tune and it gets better. I figured it was an a/f ratio issue, going rich at 4K. Oh well I will have the dynojet wideband commander functioning soon enough and then I will know for sure.

I would like to hear some other poeples guesses as to what is causing the 4K flat spot...

 

[2k3gt]

damn, i bet i have that problem. my car is slow as sin.

 

[YtnGT]

No "slow as sin" is caused by the extra 5% drivetrain loss of an auto and the extra weight (eventhough slight). You would know it if you had a flat spot at 4K rpm...