Odd Stutter @ Low RPMs

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RedninjaGT

New Member

Apr 15, 2008

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Apr 15, 2008

#1

• Apr 15, 2008

• #1

Hi Guys! I am new here and in search of what might be ailing my automatic '01 GT.

Some background, last December I replaced the IAC since it wouldnt hold an idle and it just didnt turn over one day. I replaced it and it started right up. But before and after this happened when I am cruising at a low rpm, usually around 1500, it starts shaking, "kicking", or stuttering (all words that I have used to describe it.) It sort of jerk forwards. It doesnt do this when I am excelerating or at a stop idling. I've turned off overdrive and it used to help when the car was in the lower gear, but now thats no longer helping.

I use this car as a daily driver and its getting rather annoying. Only modifications the car has is cat-back exhaust, K&N air filter, and drag springs. Shes got about 94k miles on it, and they are mostly highway miles.

Thanks guys.
-Christina

 

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Smokeurhonda

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May 1, 2003

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Apr 15, 2008

#2

• Apr 15, 2008

• #2

SOunds like it might be backlash in the gears. Is it when you are barely touching the throttle? If it is this is pretty common and normal.

 

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RedninjaGT

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Apr 15, 2008

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#3

• Apr 15, 2008

• #3

yeah its maybe when I have the throttle in 10%.

 

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Smokeurhonda

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#4

• Apr 15, 2008

• #4

Probably gear backlash. Does it feel like it's coming from the rear and kinda slaping around back and forth?

 

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RedninjaGT

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Apr 15, 2008

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#5

• Apr 15, 2008

• #5

yeah it does. What can I do to fix this or is it a dealership/performance shop fix?

 

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Smokeurhonda

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#6

• Apr 15, 2008

• #6

I've driven numerous mustangs including my own that do this, you just kinda have to learn how to change your driving style to accomidate for it. Unless there is some fix I'm not aware of.

 

2000fordstanggt

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Sep 6, 2005

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Westland, MI

Apr 15, 2008

#7

• Apr 15, 2008

• #7

Smokeurhonda said:

I've driven numerous mustangs including my own that do this, you just kinda have to learn how to change your driving style to accomidate for it. Unless there is some fix I'm not aware of.

Click to expand...

its just something you get used to..

 

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RedninjaGT

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Apr 15, 2008

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Apr 16, 2008

#8

• Apr 16, 2008

• #8

See the thing is, I commute with this car everyday for over 30 miles sitting in traffic. Its annoying and want to find out how I can fix it. My boyfriend has had many Mustangs himself and none of his have done this.

Where are these gears located? What makes it do this? I dont drive like a manic, I drive normal (sometimes with a leadfoot), and excelerating hard while driving to work every day isnt an option. I sit in too much traffic.

Please inform me, if you know, how to fix this. Thanks!

 

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99whtgt

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Aug 21, 2004

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Apr 16, 2008

#9

• Apr 16, 2008

• #9

I had a very similar problem. My 99 GT automatic would buck really hard around 1200 rpm's. This would happen almost everytime I went up a slight incline while in overdrive. I replaced the plugs and IAC and neither helped. After a bit of searching on the internet, I found that a bad Coil On Plug (COP) can cause similar symptoms. I replaced all 8 of them with an aftermarket set off ebay 2 years ago and my car hasn't stuttered since then.

 

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Smokeurhonda

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May 1, 2003

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Apr 16, 2008

#10

• Apr 16, 2008

• #10

RedninjaGT said:

See the thing is, I commute with this car everyday for over 30 miles sitting in traffic. Its annoying and want to find out how I can fix it. My boyfriend has had many Mustangs himself and none of his have done this.

Where are these gears located? What makes it do this? I dont drive like a manic, I drive normal (sometimes with a leadfoot), and excelerating hard while driving to work every day isnt an option. I sit in too much traffic.

Please inform me, if you know, how to fix this. Thanks!

Click to expand...

Here is the problem, I'm one of those mechanics that has to see and feel things to diagnose them. So it could be another problem but what you are describing to me sounds like gear lash. It comes from the clearance between the ring and pinion gears located in the rear axle housing. This clearance has to be there in a properly set up rear axle assm. The way to get around this is when your cruising and your manipulating the throttle to try to keep a steady lower speed and it starts slapping back and forth, you need to either be in the throttle more, or get out of it completely. Kind of a PITA but once you learn how to do it you get used to it it's not so bad.