Could be the coils on the electronic ignition. Have someone scan the system for codes. If none, a certified tech should be able to detect if any cylinders are mis-firing. Typically if one coil is going bad, the others aren't far behind.


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Dirty Intake. When they get gummed up, they stick closed, when you press harder on the gas, it snaps open.....

 

How do I rectify this problem

 

I now have a 2010 and in the same situation. However I just did this to my 2004 and even though the engines are facing a different direction I believe the installation is practically the same. You're going to have to remove the air intake. At this time you can clean the intake throttle (do not move the flapper without disconnecting the electronics first!) and check for any faulty wiring. (you can buy wiring harness at Fry's.) You'll also need to replace the air intake gaskets. Take your time and clean parts while you do this and it could be a bonding experience, lol. Be careful not to get anything down into your engine because it's going to be wide open!
BTW, I think you'd have a much greater problem (like codes and engine lights) if your coils were out.

 

I'm thinking you are looking at a tranny problem. This is a common issue with the tranny connected to a 3.6 liter engine on GM's in that design period. They get the "herky jerky" at mild acceleration and then if you hit harder it will go away. No one has been able to fix it. Not GM, not aftermarket, nothing. It doesn't generate any error codes and other than changing the fluid by a drain and fill for about 5 times (to clear out all the old fluid and it still doesn't get 100% doing that) and that's the only way to help the tranny. There is no filter or pan on these. There is a screen inside the trans but you would have to drop the trans for that. The only other possibilities are worn timing chains (another 3.6 common problem and yours has the mileage on it so it could be an issue) and the other being ignition coil packs on top of the plugs. You might have a bad one but it hasn't gotten to misfiring enough to set a code for the cylinder yet. (which it will eventually if it gets worse).

Good luck,
Steve

 

So with the trans flush. Since there is an internal screen, wouldn't a backward flush clear the screen and purge the crap with the flush? I've done the drain and fill 3 times, it is absolutely a poor and expensive way to clean the fluid. At a minimum, the best way would be to remove the Tranny line from the cooler and do a flush....

 

The deal with the flush is that it is "risky". Risky in that it can "dislodge" the contaminants inside the tranny. If you do that you can block other orifices that will really screw up the tranny shifting. I have a friend in the tranny business. He does not recommend the flush at all. Drain and fill (and replace filter after removing pan if accessible) is all he thinks of. All that said though I know lots of people who do the flush at a dealer with good success. But, it is risky especially on vehicles with over 50k on them. And that's because as the tranny ages it starts disintegrating internally. Clutch plates wear, the fluid looses it's viscosity and additive packages deteriorate chemically. These things combine into dirt in passages where you don't really want them. It's not like there's microscopic filters in trannys. The best ones were designs like the Saturns had. A spin on external filter. Easy to change and easy to drain. That's what they all should have (but never will in today's throw away society). And those trannys lasted. A very reliable one for sure. As for a reverse flush. It's the same problem. Dislodge the junk and you risk ruining it. But, like I said. Any tranny that is under 50k is less likely to have issues with a flush (reverse or otherwise). But, it is still risky just because if you do dislodge stuff you could be in trouble. I had a Chrysler LHS and all the online boards recommended fluid filter changes at every 30k miles due to the semi synthetic fluid and additive package they used. I followed that in mine and it was trouble free. It's up to you on what to do.

Good luck,
Steve with a friend in the tranny business.