anyone notice upon initial start up and release of clutch in neutral,speedo jumps 20 mph and back to zero,and does not do it again until initial start up.just bought on 2/14.08 ss black 5 spd,lsd.

 

Welcome to the site and forum/family.

I have experienced similar symptoms with my 2.2L shadow edition. I think nothing of it. has it affected the performance of your vehicle at all?

 

I ignore the stock speedo since it's garbage. I use my GPS, or the RPD for speed.

 

I think you're probably seeing a glitch with the VSS, when you release the clutch in neutral you still have the guts of the transmission spinning, it may be interpreting that as an output signal(the VSS is driven by the transmission). That would then be sent through the ECM to the BCM and on to the cluster giving you that little bounce of the needle.

 

thanks,new to all this electronics and turbos.I'm an ol skooler,92 s10 410 sbc,dart heads,carb.can fix anything on this myself.I love these hhr ss,wicked torque steer,by the way its a cali model,any down falls.I'm in minnesota no emission checks here.

 

I agree, There maybe a reflash to correct that but I wouldn't be too worried about it.

 

Mine doesn't do this...