It was bathering me a while back and then went away.Its a LLY motor.I started noticing it again,It seems like when you pull up to a light you feel it shake,The tach jumps alittle bit.So other than the rough idle it runs strong.I changed the fuel filter 4 k miles ago,Use power svc additive .Anybody have any ideas? Sound like she needs to go in for a check up

Have you been in for the software reflash? My truck was doing essentially the same thing. Once the dealer reflashed it, it was much better. If you have access to a Predator or some other tuner you can look at the injector balance rates. In my case with the coolant temp around 185*, the truck in drive (foot on the brake) my #2 injector balance rate would soar up to above 10 mm3.

My to only sometime rough idle when temputure is about 190

Yes ity was in that range,I did have it much worse with Edge/additude. It seemed to be much better once I pulled it.It use to also detonate around the 190 range pretty bad.sounded like a gasser with to much timing.My problem is that the rough idle is not present all of the time.Its been fine for 2 days. I still need to adress the Edgr proublem, I pulled it a while back to try to get the newest flash update and there Tech said based on my VIN I have the most current update available

I have the same symptons. Intermittent, temperature at running level. Also. looking at the passenger mirror, I'm giving off white smoke when its idling rough. I put a Tech 2 on it and one cylinder had a balancing rate in the range of 11 -12 when it is acting up. GM's limits are 4 idling in Neutral/Park, 6 idling in Drive. Got an appointment for Thursday.

Mine was doing the same thing, took it in, expecting a re-flash. Got 2 new injectors instead.

Me too! I have had the LLY in twice, once they reflashed and now - who knows. I think it is a fuel problem also. The reflash worked for a while, but now the detonation is worse and it is starting to surge and idle rough very often. I had to wait for the problem and get the tech to ride with me before they agreed to look at it. I have 25,000m and this started about 5,000 and getting worse.

Me too! I have had the LLY in twice, once they reflashed and now - who knows. I think it is a fuel problem also. The reflash worked for a while, but now the detonation is worse and it is starting to surge and idle rough very often. I had to wait for the problem and get the tech to ride with me before they agreed to look at it. I have 25,000m and this started about 5,000 and getting worse.
I'm having the exact same problems as you Miller. They have even replaced injectors in my truck. I haven't been in to get the re-flash though. Thats my next step. I'm at 26,000 miles now, and the truck surges so bad AGAIN thats its ridiculosly funny. Now its doing it alomost all the time(even when warm). I'm so pissed, i've even changed the fuel filter 5 times thinking thats what was causing this problem. Its actually kinda funny in the morning on my way to work when I stop at a light. My truck puffs so much white smoke that it looks like a fog machine. People actually stay way back from me at lights.
I stinks so bad that I can even smell raw diesel in the cab.

the idle surge could be caused by a few things. a restricted fuel filter, air in the fuel system, but the most common thing is the fuel rail pressure regulator on the pump. some people also may have concerns of a fuel knock with smoke at higher speeds. gm's reflash will not help. it may need to have injectors replaced, even then it may not fix the problem try adding stanadyne performance junior to the fuel tank, it will help.

the idle surge could be caused by a few things. a restricted fuel filter, air in the fuel system, but the most common thing is the fuel rail pressure regulator on the pump. some people also may have concerns of a fuel knock with smoke at higher speeds. gm's reflash will not help. it may need to have injectors replaced, even then it may not fix the problem try adding stanadyne performance junior to the fuel tank, it will help.
I've tried all differnt types of fuel additives. NONE of them helped. Also I think 5 fuel filters in 26,000 miles should be more than sufficent. Trucks going in for service in april while i'm in mexico. I'll mention to them to check out the fuel pressure regulator, thanks.

Took mine to george chevrolet they reflsed the program no problem yet it has been a week:)