09 LS3 Low Speed Bucking with Manual Trans
#21
Racer
Member Since: Sep 2007
Location: Mount Airy MD
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
I think ETC motor probably provides a certain percentage of TB butterfly movement based on voltage and it maybe that that percentage is not finite (sp?) enough. It' probably tunable to a point and then it is what is I would think.
#22
Race Director
Thread Starter
Member Since: Jun 2005
Location: Phila Suburbs 2023 C8 & 2013 650ix
Posts: 10,413
Received 2,221 Likes
on
1,139 Posts
Alright so yours is a little unstable also. What I don't understand is that my 05 never had any indication of this. It was smooth as silk at these speeds.
Can anyone with an LS2 engine (05, 06 and 07's) comment on whether or not they experience this instability?
Can anyone with an LS2 engine (05, 06 and 07's) comment on whether or not they experience this instability?
#23
Racer
Member Since: Sep 2007
Location: Mount Airy MD
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
Alright so yours is a little unstable also. What I don't understand is that my 05 never had any indication of this. It was smooth as silk at these speeds.
Can anyone with an LS2 engine (05, 06 and 07's) comment on whether or not they experience this instability?
Can anyone with an LS2 engine (05, 06 and 07's) comment on whether or not they experience this instability?
#24
Race Director
Thread Starter
Member Since: Jun 2005
Location: Phila Suburbs 2023 C8 & 2013 650ix
Posts: 10,413
Received 2,221 Likes
on
1,139 Posts
All I can say is that on a level road going 9 mph there is essentially no load on the motor and is almost like being in neutral. Now if you were going up a hill that might be a different story.
#25
Burning Brakes
Member Since: Jan 2008
Location: BURTON MI
Posts: 905
Likes: 0
Received 0 Likes
on
0 Posts
Alright so yours is a little unstable also. What I don't understand is that my 05 never had any indication of this. It was smooth as silk at these speeds.
Can anyone with an LS2 engine (05, 06 and 07's) comment on whether or not they experience this instability?
Can anyone with an LS2 engine (05, 06 and 07's) comment on whether or not they experience this instability?
#26
nm.
Last edited by C5 Hardtop; 08-29-2009 at 04:40 AM. Reason: can't read :D
#28
Melting Slicks
My car does this too. I never noticed it until I read this post and took the car out for a slow ride up and down my street. My car will not idle between 600 and 1100 either when in neutral. I've never had any bucking problems in traffic since I usually shift into 2nd gear if it's a steady 5mph or more...but it did "buck" slightly in this particular test ride... '08 Z51 MZ6.
#29
Racer
Member Since: May 2006
Location: Peterborough NH
Posts: 267
Likes: 0
Received 0 Likes
on
0 Posts
Mine does this also at very low speed. I have an 08 base MN6. I have posted about a related problem as well -- when you are cruising at steady speed and have your foot on accelerator just barely depressed, say going 40 mph in 4th gear, I can feel the slight "bucking" or "surging". I think it is the throttle by wire (or lack of wire). The dealer says if no codes are showing there is nothing they can do. For now I am just living with it. When my foot is into it there is no problem -- only at very light throttle is there an issue. I also have difficulty, when stopped, revving the rpm's into the 600 to 1000 rpm range. I think it is the throttle, which is very touchy between not depressed and slightly depressed. It makes me depressed sometimes.
#30
Race Director
Thread Starter
Member Since: Jun 2005
Location: Phila Suburbs 2023 C8 & 2013 650ix
Posts: 10,413
Received 2,221 Likes
on
1,139 Posts
Any LS2's (05 to 07's) with this problem? I think it's confined to just the LS3 engine.
#31
Tech Contributor
#35
Pro
Member Since: Sep 2009
Location: Los Angeles California
Posts: 536
Likes: 0
Received 1 Like
on
1 Post
I'm not experiencing the problem, so I may not fully relate, but I'd say a normal pull-away from a stop in these cars sees full clutch engagement at about 1500 rpm/12mph. If you get the clutch closed much below 1500 rpm I would kind of expect the car to be bucky, and hyper sensitive to the slightest throttle changes. All manual cars are like that to some extent, and the vette has tall gearing, which is bound to raise the "minmum smooth creep speed"
#37
Safety Car
I'm not experiencing the problem, so I may not fully relate, but I'd say a normal pull-away from a stop in these cars sees full clutch engagement at about 1500 rpm/12mph. If you get the clutch closed much below 1500 rpm I would kind of expect the car to be bucky, and hyper sensitive to the slightest throttle changes. All manual cars are like that to some extent, and the vette has tall gearing, which is bound to raise the "minmum smooth creep speed"
#38
I have a 2007 LS2 standard that is having this exact problem. I bought the car with 3000 miles on it. It didn't seem to do it when I bought it. It now has 11,000 miles and does it pretty much constantly. Low RPMs, 2nd and 3rd gears between 25 - 40 MPH. If you apply slight accelerator or release the accelerator it bucks and jerks. I've had it to the dealer twice now and they haven't found or done anything. Not sure what to do next...
#39
Drifting
09 Z-51 MN6. I have this too. I've been calling it a "surging" at 1500-2000 rpms at a steady cruise in 2nd or 3rd. Does it do this worse when cold? When you come to a stop do your revs climb a little and then drop back down?
#40
It doesn't seem worse when cold. I've tried to monitor to see if certain conditions aggrevate it but I haven't found anything particular. The funny thing is I had the actual corvette mechanic at the dealer ride with me and he acknowledged he felt the issue. I left it with them for 2 days and they told me that they didn't find anythig and there was nothing else they could do. I do get the rev climb you mention when coming to a stop but it's not all the time.