hey guys, i have a 2006 Ls with 138k on it. The past few weeks when i start it, it will idle very rough, ie go from around a 1000rpm to 2-300 then bounce back up and do this for a little while, i usually give it gas to about 2k and let it sit for a minute and its fine, it only does this sometimes though and it doesn't matter if the car is hot, cold, or been sitting all night, once its running and driven it idles fine, any ideas? I'm kind of at a loss

 

Hey rocket, I was gonna post the same thing on a rant about gm service! My check engine light was on so i took my ls with 82000 miles to the dealer. My mileage was down, engine heat not stable and that same rough idle. They told me it was the cat plugged up and that they'll goodwill it to me since i went past the warranty. But in oder for them to do that they charged me for injector service(cleaning), coolant flush and trans flush. Now i have 87000 and the rough idle is back. It's not bad enough to trip the check engine light, but it's like maybe 1 injector is going bad. On top of that they charged me $450 bucks. Long story but I'm just saying that to suggest taking it to a local shop instead of gm. They're after the $$ and don't care if you're shyt is fixed 100% right. If you just want to tinker, try changin the fuel filter, air filter and spark plugs. Also run some injector cleaner and see if that helps.