clperkins53

i have a 2009 corvette base ls3, when i start the car, it runs real ruff and then after about 30 seconds it smoothes out. have checked about everything and can't find any problems with anything. any suggestions.

SleepyWeasel

My 2012 does the same thing. Have not taken it in for service yet.

R&L's C6

Mine does it too, chalk it up to normal.

Z51vette88

MMine kinda sounds cammed on cold sstarts especially with the dual mode. if there's no cel I wouldn't worry about it

JimmyLee

Agree...there have been several posts about this before.

Vet Interested

My 2010... Same thing. Mine even does it at idle sometimes after a drive. Took it to the dealer. Put it on a computer. Saw no evidence of any misfires. And said it was good to go. Feels like a mild cam is in it.

red2012

My 2012 did it and my now 2013 GS does it also thou not as much. Did have the car checked and dealer found nothing on the tech 2. Normal

SCcues

Mine has done it since I bought the car and it sounds like it has a mild cam. I like the way it sounds and it's totally normal for a LS3 motor. I think the LS3 is a great engine. Good fuel economy and plenty of get up and go.

Rky Mtn C6

Same for my 2012 GS. Car shakes, and it's rough for about 10-15 seconds, then smooths out. Dealer and Corvette specialty shop both said it's common/normal for the LS3s.

Red08

I am not sure that running rough for 30 seconds should be considered normal. My 2008 LS3 is smooth upon start up, as well as the other two vehicles I drive, so I considered a smooth start normal. NOt saying it is hurting anything, but I don't think it is normal.

Cowboy26a

My 1012 Grand Sport has a mild lope to it at idle. I asked my cousin about it the other day and he said his 2010 Grand sport does the same.

Kraz8s

Normal LS3 cold start.

hawkgfr

Normal...if you pay attention when its cold outside is doesn't do it.....If its like 60-100 out side it sounds like a big cam race engine for about 15 seconds....


I love it...but my ls2 never did it.

owc6

I agree. The LS3 idles much more roughly than the LS2. But it is normal.

phileaglesfan

It is normal, every single C6 I owned did it. It is part of the character but GM probably did it to give it more HP. The 6.2 in my Denali was smooth as possible but it had 20 less hp.

Huskerman

I'm glad I'm not alone......My 10 GS does the same thing at start up. After having it checked out and nothing found wrong and talking to some mechanics we came to the conclusion that there might be an injector or two letting some raw fuel into the cylinder and that is what is causing the rough starts........after my car is warmed up and I shut down and restart within 10 or so minutes it starts smooth....any more than that I get a rough start again....

Anyway that's my story and I'm sticking to it.....may not be that at all....but it sounds good anyway.....

phileaglesfan

If the engine is just "loping" a bit then that is normal. Sorry, but GM put a slightly more aggressive cam in.

Having a cylinder misfire will not be loping. All 3 of my C6s idled at about 550 rpm +- about 50-100rpm.

Unfortunately it is just another normal operating characteristic for the engine to lope. Almost like the brake switch clicking or a bunch of other things GM calls normal operation.

1rusty1

Yup. Rough idle is normal. Every one I drove had it.

Mad*Max

mine is smooth at start up, however, once it warms up the idling get rough (slightly)

DenverdansC6

My 2010 GS that I got 2 months ago does the same thing, but it smooth's out within about 10-15 seconds. I don't recall my previous 2010 doing it. Glad to hear it seems to be a common issue and not a problem.