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transmission/torque converter issue?

29663 Views 35 Replies 13 Participants Last post by  rakesb27
2008 g6 with 3.5L v-6
my problem is when the car shifts to 3rd or 4th gear, (only under light to moderate acceleration) the tach needle jumps up and down about 200 rpms or so, and it can also be felt in the drivers seat as a slight bucking. its especially noticable going up a slight hill. its almost like the torque converter is trying to lock, and unlock. but here is the strange thing, if the car is cold, it doesnt do it, or if its fully warmed up (driven 10 miles or more) it doesnt do it. seems to be the worst just after it hits full operating temperature on the gauge. i have taken it to couple dealers but they either say its normal, or cant find anything wrong. usually i can figure this stuff out and fix it myself, but this one is difficult. as it could be any number of things. anyone out there encountered this problem in either your g6, malibu or aura?
let me know, thanks.
oh, and i did have the flash update done, but it didnt help.
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I have had the exact same problem with my t converter. After bitching about it enough times to the dealership, they finally replaced it, however I still have the same problem but now right at the 38-39mph mark.
Hi All,
Well I changed my spark plugs and wires still have the problem, but when I was changing out the plugs and wires I notice that number 5 boot was not on the spark plug all the way, still was not the problem. I have been to the dealer 2 times for this and the last time they gave me a "Data Can" which is just a data recorder that activates when you press a button and records everything about the transmission at that time. Well I did this four times and gave it back to the dealer. They analyzed it and said there is nothing wrong with the transmission. Well at 38-39mph I get this shuttering and sometimes it is very violent. I have a open case with the customer service department at GM, but so far no help. The dealer say's nothing happens when they drive it, also they told me that they do not pay their mechanic to drive cars, And that if you have no codes, you have no problems.
My darling wife wants to get rid of it and buy a Ford. Can't blame her, it's her car.
Now I am going to see if I only use the “Manual Shift” and see if it happens.
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My 2008 g6 with a 2.4 was floating 200 rpm at 55 to 60mph. I took the car to a trans shop and they told me it needed a bad tuneup or cat. They told me it would not make enough power for the trans to shift correctly and the trans was fine!! 77,000 miles. They have a history of having bad cats!! I found the cat was plugged and cracked!!
One of my cats went out at about 65000. When I started searching I found alot of GM owners having the same problem
The plugged cat did not solve the floating rpm problem. I took it into the dealer for the transmission problem this time and they told me they could not find any problems with it. They say this is normal. As far as the rpm problem goes they told me they would not worry about it/it must be electrical. It seems to me that the converter is not going into lockup, but I guess it is?? If anyone else has come up with the solution to this problem/if there is one?? Please reply with the fix. If there is one?
I was having the same issue with my car. It started after i cleaned my air filter and oiled it. The problem didn't just show up right after i cleaned my air filter. It slowly creep-ed up on me, only doing it once in a wile and soon after that it was doing it all the time. Then one day coming home from a 300 mile trip it started to do it at all rpms. I changed my plugs and wires, but that didn't help out.

What it turned out to be was the oil from the air filter contaminated the mass air flow sensor. I picked up some maf cleaner and it cleared up it up for the most part.
Hi All,
Well I brought my car back to the dealer again because the shuttering problem has gotten worse. Also I started getting a cluck noise in the steering.
Just off the phone with the service manager and he said that I need a new intermediate shaft for the steering cluck and that my torque converter is bad.
Finally getting it fixed. But they have to order the parts, take about a week.
I will post back after it gets fixed and let you all know if it really is fixed.
My wife is very happy that they finally agree with us that there is a problem.
you sure there wasn't a chicken stuck in your dash behind the steering wheel?
you sure there wasn't a chicken stuck in your dash behind the steering wheel?
Dam I can"t spell. lol
Just so you all know how the tech found the problem was that he had his scan tool hooked up to the car, while driving at 45mph he used his scan tool to commanded the torque convert to look-up, that's when the car started to shutter.
I guess I am happy they found the problem, but why didn"t they do that the first time I brought it in 16,000miles ago, or maybe they did and it didn't cause the problem then?
It should be fixed in about a week or so, I'll let you all know how it goes.
Well they replaced the converter and i still have the problem and is getting worse. Now it is slipping....let off the gas going into a corner then step on it.
The RPMs go to red line and the speedometer does not change, then a few seconds later it engages. Happen 5 time now with me driving it.
Bring it back... oh what fun. BTW: no codes.
Hi All,
Brought my G6 GT back to the dealership, they found the problem with the slipping when going into turns.
It was the Transmission filter was not installed correctly and was just about to fall off.
How is that I asked if the filter is lock into place and only you have worked on my transmission. He had no answer to that.
Then the service manager tells me that the shuttering that I feel when I try to maintain a speed of 38mph has no fix for it. They contacted GM technical and the service manager said that GM said “Do not work on that car, there is no fix for it”. And he also said that they have a boat load of customers complaining about this.
I still have a hard time with this. I bought a brand new car with warrantees and they tell me there is no fix. What good is the warrantee if they don’t fix it.
Not happy at all. I have to take the next step. I will not take this sitting down.
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good for you...contact pontiac and just keep asking for someone else higher up until you get what you need. if your warranties are still valid then you definitely have a right to get this fixed.
Torque Issues

Jessix and all,
I had the same issue with my 08 G6 3.5 and I bought new plugs and wires. The technician that put the car on the machine drove it and said that it is miss firing on one of the plugs - so even though it start at 75000 miles i had them replace the plugs and wires and they found that one of the plugs had scorch marks on the plug so the spark was not going thru the plug fully. It did resolve the issue with the hesitation on low speed during 40 thru 60 or in between. The big complaint that i do have with the G6 is the I-Shaft clunk at low speed when turning. The GM service group greased the I-Shaft (aka Steering Column) once when i complained the first time but when i went in a little over a year later with the same complaint - they hesitated on saying that it should be replaced and said that since my limited warranty was up that i would have to pay for the replacement. I hear from others that they are having the same issue along with other models and that nobody will take the blame for the fault with the I-Shaft issue. It should be part of a recall that should be replaced by the manufacturer but that will never happen. So I deal with the noise on occasion.
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There is no fix, because they don't know how to fix it.
I have a 07 g6 gt 3.5 transmission won't change-up of high gear just homes, is it a bad transmission.
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