A6 transmission issue
Thread Starter
Burning Brakes
Joined: Sep 2011
Posts: 942
Likes: 0
From: Dallas/Fort Worth TX
A6 transmission issue
So I had cams, headers, 160 thermo, CAI, and tune on my 2012 automatic grand sport. The car is great when I stomp on the gas, but when I let off the gas or am at even throttle at certain speeds, it will buck/jerk.
2 separate shops that are highly reputable plugged in and said what is happening is not related to the tune or the cams. The shop that did the original work noticed the converter was going nuts at even throttle or when coasting at certain speeds. I paid up to put in a circle D triple disk 2800 stall converter. Not a cheap mod. I am still having the same issue with the car bucking/jerking. This is not a small buck from the cam. Both tuners said this is very odd and seem to feel the issue now lies in the transmission.
If the issue is the transmission, what part of it could cause the converter to lock/unlock in an abnormal fashion, which is apparently what is causing the bucking and taking all the fun out of driving the car?
2 separate shops that are highly reputable plugged in and said what is happening is not related to the tune or the cams. The shop that did the original work noticed the converter was going nuts at even throttle or when coasting at certain speeds. I paid up to put in a circle D triple disk 2800 stall converter. Not a cheap mod. I am still having the same issue with the car bucking/jerking. This is not a small buck from the cam. Both tuners said this is very odd and seem to feel the issue now lies in the transmission.
If the issue is the transmission, what part of it could cause the converter to lock/unlock in an abnormal fashion, which is apparently what is causing the bucking and taking all the fun out of driving the car?
Supporting Vendor
Joined: Feb 2011
Posts: 3,520
Likes: 880
2024 C6 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (track prepared)
2019 C6 of Year Winner (track prepared)
So I had cams, headers, 160 thermo, CAI, and tune on my 2012 automatic grand sport. The car is great when I stomp on the gas, but when I let off the gas or am at even throttle at certain speeds, it will buck/jerk.
2 separate shops that are highly reputable plugged in and said what is happening is not related to the tune or the cams. The shop that did the original work noticed the converter was going nuts at even throttle or when coasting at certain speeds. I paid up to put in a circle D triple disk 2800 stall converter. Not a cheap mod. I am still having the same issue with the car bucking/jerking. This is not a small buck from the cam. Both tuners said this is very odd and seem to feel the issue now lies in the transmission.
If the issue is the transmission, what part of it could cause the converter to lock/unlock in an abnormal fashion, which is apparently what is causing the bucking and taking all the fun out of driving the car?
2 separate shops that are highly reputable plugged in and said what is happening is not related to the tune or the cams. The shop that did the original work noticed the converter was going nuts at even throttle or when coasting at certain speeds. I paid up to put in a circle D triple disk 2800 stall converter. Not a cheap mod. I am still having the same issue with the car bucking/jerking. This is not a small buck from the cam. Both tuners said this is very odd and seem to feel the issue now lies in the transmission.
If the issue is the transmission, what part of it could cause the converter to lock/unlock in an abnormal fashion, which is apparently what is causing the bucking and taking all the fun out of driving the car?
While it could possibly be tuned out by making adjustments to the engine, the better solution would be to have your torque converter not command lockup until you reach freeway speeds. The advantage of doing this is twofold - one, not having the converter locked up will absorb all the bucking you feel and two, it makes the engine much more responsive (and fun) to drive around town because if you step on the gas you don't have to wait for the converter to unlock before the car wants to go.
The only downside is that your transmission will run slightly hotter but this can be remedied by a transmission cooler which you should probably already have if you don't yet.
If your tuner isn't quite sure how to change the lockup settings, feel free to email me directly as the PM notification here doesn't seem to be very quick these days.
Hope that helps,
Christopher
syclone98@hotmail.com
Thread Starter
Burning Brakes
Joined: Sep 2011
Posts: 942
Likes: 0
From: Dallas/Fort Worth TX
It's definitely the cam and the bucking you feel is likely caused when the torque converter clutch is locked up, synonymous to the bucking people experience in manual transmission cars when they're in higher gears and under light load.
While it could possibly be tuned out by making adjustments to the engine, the better solution would be to have your torque converter not command lockup until you reach freeway speeds. The advantage of doing this is twofold - one, not having the converter locked up will absorb all the bucking you feel and two, it makes the engine much more responsive (and fun) to drive around town because if you step on the gas you don't have to wait for the converter to unlock before the car wants to go.
The only downside is that your transmission will run slightly hotter but this can be remedied by a transmission cooler which you should probably already have if you don't yet.
If your tuner isn't quite sure how to change the lockup settings, feel free to email me directly as the PM notification here doesn't seem to be very quick these days.
Hope that helps,
Christopher
syclone98@hotmail.com
While it could possibly be tuned out by making adjustments to the engine, the better solution would be to have your torque converter not command lockup until you reach freeway speeds. The advantage of doing this is twofold - one, not having the converter locked up will absorb all the bucking you feel and two, it makes the engine much more responsive (and fun) to drive around town because if you step on the gas you don't have to wait for the converter to unlock before the car wants to go.
The only downside is that your transmission will run slightly hotter but this can be remedied by a transmission cooler which you should probably already have if you don't yet.
If your tuner isn't quite sure how to change the lockup settings, feel free to email me directly as the PM notification here doesn't seem to be very quick these days.
Hope that helps,
Christopher
syclone98@hotmail.com
Both tuners have put similar packages on a corvette countless times (there's not much to headers and cams) and haven't seen anything like this before. They remain convinced this buck is not from the cam. They say it is something in the transmission causing the converter to lock/unlock in an unpredictable fashion. I've gone to 2 of the top 3 most reputable performance shops in town, and they both say the same thing.
Keep in mind the car is fine when I'm on the gas, it is only at steady or no throttle at certain speeds where the buck happens, and both tuners said this is not a normal buck from a cam.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
so you've got about 4 different new items going on (cam, headers, tune and tq convert.). sounds like something in the trans to me, if two shops say it's not the cam. what happens if you use stock tq converter---same bucking? or did you not have that in when it started bucking after the cam/header installation?
Thread Starter
Burning Brakes
Joined: Sep 2011
Posts: 942
Likes: 0
From: Dallas/Fort Worth TX
so you've got about 4 different new items going on (cam, headers, tune and tq convert.). sounds like something in the trans to me, if two shops say it's not the cam. what happens if you use stock tq converter---same bucking? or did you not have that in when it started bucking after the cam/header installation?
Thread Starter
Burning Brakes
Joined: Sep 2011
Posts: 942
Likes: 0
From: Dallas/Fort Worth TX
Wound up being the tune. Apparently the tuner left fuel trims turned off and had the stock transmission tune on my car, which doesn't make a lot of sense. In any event, I found a tuner that fixed it. I am relieved it wasn't something more serious. Turned on fuel trims and modified tranny tune and car is much happier!
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,718
From: Springfield MO
Wound up being the tune. Apparently the tuner left fuel trims turned off and had the stock transmission tune on my car, which doesn't make a lot of sense. In any event, I found a tuner that fixed it. I am relieved it wasn't something more serious. Turned on fuel trims and modified tranny tune and car is much happier!
