What is your G8 GT's RPM at idle? I heard that is what is causing the "rough idle" because the factory setting for the rpm at idle is too low and causing it to sputter and in some cases shut down. My current car's rpm at idle is about 1000 rpm. My dad's chevy suburban (GM V8) is about 500 rpm.

I will have to check mine when the fiancee gets back from the bank. I want to say ours is around 500. I know it's no where near 1k. I also very rarely get that vibration.

Just checked, ours idles just above 500

Just checked mine a bit ago, with the motor at operating temperature, it's running about 560 RPM.

ok. Thats about what my dad's 2002 chevy suburban LS run's at idle. About 500 but it is very smooth at idle with very little to no vibration. Maybe it's not a 6.0 V8. I hear cars should be from 700 to 1K at idle. Don't quote me on that though it might be wrong.

1k seems pretty high

Im not sure if it's high or not. I just know my car i have now (1999 mercury sable GS) rpm at idle is about 1100 rpm. It's quiet and smooth at idle. It may be high but it's working :).

mine is about 560 too

1000 might be where a manual should idle, but that's too high for an automatic.

I need to get my Dashhawk out. Looking at the tach, it's slightly above 500 in drive.

I need to get my Dashhawk out. Looking at the tach, it's slightly above 500 in drive.You can use engineering mode to check the idle RPM's also and get a digital readout.

600 rpm

600 rpm

Yours is a bit above everyone else's. How does your GT feel like at idle?

GM (and everyone else) tries to get the idle as low as possible for better fuel economy, but not too low to be rough or stall. One of the tricks used by car manufacturers to smooth out idle is to have the rear window defrost come on at startup, due to the slight load.

Some engines do have purposely high idles, such as hybrids and high performance vehicles.