Resurrecting this thread. Has this problem been diagnosed or solved yet? I've had my '09 SS for about 2 weeks now, I have experienced this on a few drives so far. Today I pulled out of the garage and this happened on every shift. In 5-6 minutes I was on the freeway and it no longer happened. Not sure if it matters, but I was also, during this 5-6 minutes, experiencing the intermittent problem of difficulty shifting. Feels like if I just had another 3/4" of clutch travel before hitting the floorboard, than it would be OK. So this rev problem today was even more frustrating because it was between gears for several seconds, revving at about 3500 RPM.

 

I don't really know any thing about this issue, but post #47 in this thread sure has an interesting theory on it.

 

Yes, but that is not the solution, that is the problem. having the clutch pressed and the engine revs without your foot on the accelerator pedal. Unless... this is part of the No Lift Shift. The moment you touch the clutch pedal the ECM senses throttle position and holds that RPM until you complete the shift? But I think you're only supposed to have about 1 second to complete the shift, the ECM is holding RPM for several seconds. sounds like a malfunction to me. To have to completely remove foot from accelerator prior to touching clutch pedal is ridiculous.

 

In red above ^ Like I stated, I'm not familiar with this high idle issue, but that description makes me wonder if it's just a throttle position problem you have, if you're leaving your foot "on" the accelerator when shifting.

Fwiw. NLS(no lift shifting) , from what I understand, is almost a gimmick thing. GM just stuck a rev limiter on these cars, then realized you could shift the SS tranny without lifting the accelerator. Rev limiter was supposed to keep you from over taching it while doing the NLS, plus keep the boost built up.
I don't believe there is any special programming in the ECM for this feature.
I think GM just used this extra "feature" as a free advertising gimmick for the SS sales features.

 

a) I know nothing about SS
b) it's been 15 years since I drove a standard regularly

I have always lifted off the throttle simultaneously with depressing the clutch, even when "speed shifting". Is that what you are talking about? I have driven close to a million miles on standard transmissions, never driven a boosted vehicle, it just seems natural to me to do it that way.

Maybe there is a vacuum switch or spring thingy somewhere under the hood that could malfunction? A bad TPS should throw a CEL.

 

Yes, I agree Don, that's how I've always shifted also. No CEL, and I just bought it from a dealer 2 weeks ago, and it had already passed California smog, so it shouldn't have thrown a CEL anytime in recent time. Guess I'll have the mechanic check for any codes.

 

I’ll preface this by saying: I hate resurrecting old threads, but this issue seems to have gone unresolved, I’m experiencing it, so I’m resurrecting it.

I’ve been driving manual transmission cars since I was 18. I’ve worked at multiple GM dealers and have driven a plethora of different manual trans cars. I say that to quantify my position on this subject.

Whatever this problem is, it is a problem with the car, not the driving style.

I don’t have a warranty, so I’d really like to try and get a feel for what’s causing this rather than dumping it on a dealer and paying an unknown amount for diagnosis of a problem no one seems to have been able to address in the 7 years since this car came out.

For me, the problem is intermittent (also backing up the thought that it is a problem with the car, not driving style).

It occurs mostly when warm.

It will occur *sometimes* when hitting the back streets after driving on the expressway for a while.

It occurs (almost) every time you start (and drive) the car after it’s already hot (i.e. a quick run into the store or run into the house for something).

When it occurs, you will experience the RPM’s jumping 500-1000 RPM when the clutch is depressed as a part of your normal 1-2 and 2-3 part throttle shifts. (2500 to 3500 RPM shifts , not spirited acceleration).

If you hold the clutch in with the foot OFF the gas, the RPMs will SLOWLY (much slower than normal) drop back towards the normal idle RPM. IF you continue to keep the clutch depressed and hit the gas, the RPM’s will jump up substantially and (once again) take a much longer time (than normal) to return to idle.

So far, I’ve found only one thing that has any effect on it. When it is occurring, if you lay into the throttle at lower RPM in 2nd, wait until it builds full boost, them jump completely off the gas (to the point the BOV has to release the pressure) it will drive normally for a while. You may be able to do this in 1st as well, but you go through it so quick, it's easier to control the process in 2nd.

I’ve thought of maybe a weak motor in the throttle body (or a weak return spring), but I have nothing definitive.

I’m hoping that this description of this issue triggers something in someone’s thoughts that leads to a diagnosis.

This issue is REALLY annoying (and embarrassing; as others have said, it makes it appear you are completely inept as a driver) .

 

I think as you do sticky TB or the gears are dry in the TB, or just a dirty TB .
Give it a cleaning and the MAF too!

 

I had a Toyota pickup that did something like that a long time ago (in the '80's). IIRC, it was a vacuum leak, I really only remember the part about feeling like a rookie missing gears shifts.

 

I had turned off notification to this thread, so I missed it's revival.

I have not experienced this issue in quite some time, can't remember the last time. The only change I can think of that may have affected this problem is when I was having
These problems

The clutch pedal position (CPP) sensor and the brake pedal position (BPP) sensor are the exact same part. I swapped them, can't remember if the problem persisted for a while or not, but it's free, and it may have fixed it.

These are rotary sensors. Perhaps, depending on which pedal it's on, it uses a different part of the sensor. i.e. maybe on the brake it uses 9 oclock to 3 oclock, and on the clutch it uses 3 oclock to 9 oclock. IIRC (which I often do not) I had to "turn the dial" quite a bit more to get it on the brake pedal.

What I'm trying to guess at, is that maybe my CPP sensor was bad on the clutch pedal, but worked fine on the brake pedal. Or maybe the car just decided to stop malfunctioning on it's own. But it's a free try to fix the problem.