LS3 Deceleration Shudder
03-06-2010, 09:36 PM
#1
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St. Jude Donor '13
LS3 Deceleration Shudder
Car is a 2009 Coupe, A6, performance axle (Z51).
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
03-06-2010, 11:53 PM
#2
Race Director
Jim just went for a drive to check mine out though it is a manual. I would not say it is a shudder. Below 1000rpms I feel the engine is lugging. But I will tell you at idle 800rpms seems to be impossible. Idle or 1100 seems to be the rule.
Last edited by TMyers; 03-06-2010 at 11:55 PM.
03-07-2010, 07:43 AM
#3
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St. Jude Donor '15
"In honor of jpee"
Man. trans also, Jim, but mine is like TM's above. Haven't felt the shudder. Hopefully, others w. auto trans will chime in. 
03-07-2010, 11:32 AM
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Car is a 2009 Coupe, A6, performance axle (Z51).
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
Jim: I've experienced same off throttle driveline shudder you described (08 C6 Coupe A6 19K miles). Mine is a ZHZ so I thought perhaps it was result of previous abuse. Not happy to hear of your experience, but glad to know if others are having similar experience (esp. on an 09) mine may not be abuse related.
03-07-2010, 11:40 AM
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You could try cleaning the throttle actuator. Other than that, I can't think of anything that would cause the issue.
At almost 20k on the clock of our 09 I have never had this issue with our A6 Vette
03-07-2010, 01:35 PM
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Car is a 2009 Coupe, A6, performance axle (Z51).
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
03-07-2010, 02:21 PM
#9
Melting Slicks
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You know, another thought here. Is is possible that you're entering a fuel cut-off area of the map during decel? There is an area of the map during decel that is there to save fuel during no-throttle decel. Maybe that's what you're experiencing?
03-07-2010, 04:01 PM
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08 auto with 34k has been doing the same thing for about a year. Instead of getting off the gas gradually to coast I lift off quickly to minimize the shudder. I figured it was a normal driveability problem but never mentioned it to the dealer. I will now.
03-07-2010, 04:20 PM
#13
Intermediate
Mine is an 09 1LT A6 and I have noticed the same thing, sometimes to me it feels as if the trans is stuttering while shifting down. I thought I might be the only one having this issue. I have not noticed any other symptoms, there is no slippage, and the upshifts feel crisp. I have tried changing back and forth between D and S but it really doesn't matter. I have noticed it doesn't seem to do it if I manually downshift with the paddles. It has left me scratching my head.
03-09-2010, 01:41 PM
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My stock '08 A6 has never done this.
It did sort of "hunt" or hesitate after a strong speed up like pulling up a short on ramp to the freeway and then letting up to let traffic by when I could see it. When I'd get back on the throttle I'd feel that hunt or hesitation before it would get going again.
There was a software upgrade for improved torque management for the A6 and I just had it done a couple of weeks ago and the problem has completely disappeared.
I'd suggest you take it in and ask for the latest reflash for the transmission. Additionally my dealer said there were a ton of other ECU updates related to drivability issues. They didn't say which ones they updated, but the car feels much smoother.
It did sort of "hunt" or hesitate after a strong speed up like pulling up a short on ramp to the freeway and then letting up to let traffic by when I could see it. When I'd get back on the throttle I'd feel that hunt or hesitation before it would get going again.
There was a software upgrade for improved torque management for the A6 and I just had it done a couple of weeks ago and the problem has completely disappeared.
I'd suggest you take it in and ask for the latest reflash for the transmission. Additionally my dealer said there were a ton of other ECU updates related to drivability issues. They didn't say which ones they updated, but the car feels much smoother.
03-09-2010, 01:48 PM
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Car is a 2009 Coupe, A6, performance axle (Z51).
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
If I'm driving along about 50 mph and ease off the throttle, the driveline will shudder for a second or two when the throttle is almost closed. If I release the throttle very quickly, the shudder will still happen but it's milder and stops sooner.
The LS3 engine does not like to take light throttle opening, several members have posted about how they can't get the engine to hold something like 800 rpm in neutral, it jumps from idle to about 1100 rpm.
I suspect my shudder is caused by the "light throttle" issue, but can't tell for sure.
Does anyone else have this problem?
Is there a fix?
03-09-2010, 02:14 PM
#20
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No problem, just smooth as ever.
I have a 06 C6 A6 and it has always been smooth except for the bad gas I had once. Put the water eliminator in the gas tank and solved the problem.