07 Impala SS 4th gear bump
Thread Starter
Teching In
Joined: Jan 2011
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07 Impala SS 4th gear bump Hello i just bought a 07 impala ss it has 72000 miles when driving it will shift fine in all gears but when in 4th gear tach will be at 1500 to 1600 rpms then it feels like a bump and then the rpms go down to 1200 to 1300 rpms the guy i bought it from put a thirty day warranty on it just want to make sure it is ok thanks
Thread Starter
Teching In
Joined: Jan 2011
Posts: 6
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im new to this car would dod cause a jerk like that i had it scanned there are no codes checked for updates from gm it is up to date im just nervous after reading all the post on here about transmission problems
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My car had the same issue. Cruising on the freeway at 70-75, I noticed a surging. When going up hills, it would be more obvious and jerky.
The first dealer I took the car to was not able to find anything wrong with the car. The dealer updated the PCM and sent me on my way without fixing anything. Fast forwarding a couple weeks, the car was not able to move forwards or backwards, I had the car towed to another dealer. The dealer replaced my torque converter and I have not had any surging since then.
You have a 2007, meaning you still have the factory 5 year/100k mile power train warranty. All of the parts and services the second dealer did on my car was free.
The first dealer I took the car to was not able to find anything wrong with the car. The dealer updated the PCM and sent me on my way without fixing anything. Fast forwarding a couple weeks, the car was not able to move forwards or backwards, I had the car towed to another dealer. The dealer replaced my torque converter and I have not had any surging since then.
You have a 2007, meaning you still have the factory 5 year/100k mile power train warranty. All of the parts and services the second dealer did on my car was free.
TECH Enthusiast
Joined: Nov 2008
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Well you drive a chevy so you have the option of pressing the top button on your DIC control(right side of cluster) and selecting instant economy . It will show you that/when it is in 4/8 cylinder mode.
You also have another option, which the pontiacs don`t... drop it in 3rd and the DoD/AFM is totally disabled and see if you have any abnormal surges/bumps.(personally I never allow Dod/AFM engagement under 80kph/50mph or use 4th gear for that matter)
Our cars are known for a amplified engagement/disengagement when the Throttle body and/or Mass AirFlow sensor are dirty.Simple DIY if you can handle simple hand tools and a spray can.
You also have another option, which the pontiacs don`t... drop it in 3rd and the DoD/AFM is totally disabled and see if you have any abnormal surges/bumps.(personally I never allow Dod/AFM engagement under 80kph/50mph or use 4th gear for that matter)
Our cars are known for a amplified engagement/disengagement when the Throttle body and/or Mass AirFlow sensor are dirty.Simple DIY if you can handle simple hand tools and a spray can.
I still have DoD.
When I had my last sloppy factory torque converter, you could not feel the transition between 4 and 8 cylinder mode. Now that we have a tighter converter, we do notice a slight surge during that transition.
GM used a loose converter in our cars, along with torque management, to soften the 4-8 transition. Now, there's a huge car-to-car variance from the factory in the stall of our torque converters The first three I had in my car were all different from each other, and I could feel the transition from 4 to 8 cylinder mode differently in each one.
My guess is, you've got a tighter converter in yours, and it doesn't mask that transition very well.
The only other thing I can think of is, you could have an aftermarket tune with the torque management removed, which will also cause the surge.
When I had my last sloppy factory torque converter, you could not feel the transition between 4 and 8 cylinder mode. Now that we have a tighter converter, we do notice a slight surge during that transition.
GM used a loose converter in our cars, along with torque management, to soften the 4-8 transition. Now, there's a huge car-to-car variance from the factory in the stall of our torque converters The first three I had in my car were all different from each other, and I could feel the transition from 4 to 8 cylinder mode differently in each one.
My guess is, you've got a tighter converter in yours, and it doesn't mask that transition very well.
The only other thing I can think of is, you could have an aftermarket tune with the torque management removed, which will also cause the surge.