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Old Mar 30, 2011 | 05:09 PM
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Default Rough idle

I have had my car for three weeks and seems like the idle is a little rough. I traded in my 2010 ss camaro and it to had a rough idle. Sometimes in the morning it would shake the whole car.
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Old Mar 30, 2011 | 05:16 PM
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If it's a 2010 GS w/MN6 built by Mr. Geise @ Wixom, he may have slipped in a ZR1 cam like he did mine. That would attribute to the rough (cam lopping) idle...
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Old Mar 30, 2011 | 05:21 PM
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Check spark plug wire connection.
Could be bad gas.
Deposits on plugs or maf.
To much low rpm operation.
Just some thoughts.
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Old Mar 30, 2011 | 05:22 PM
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Normal only lasts a short time, enjoy.
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Old Mar 30, 2011 | 05:25 PM
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Normal until the engine warms up a bit.
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Old Mar 30, 2011 | 05:29 PM
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I've felt that way about mine too..but, it does seem to go away after it warms up.
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Old Mar 30, 2011 | 05:42 PM
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Try cleaning the throttle body. You can get carbon/dirt buildup at the butterfly which can keep it from seating properly. I do mine every 6000 miles or so.
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Old Mar 30, 2011 | 06:21 PM
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I do mine every spring just to keep things nice and clean
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Old Mar 30, 2011 | 06:50 PM
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Originally Posted by c6vette
Try cleaning the throttle body. You can get carbon/dirt buildup at the butterfly which can keep it from seating properly. I do mine every 6000 miles or so.
Pretty easy to pull off and clean and can be the cause of rough idle in addition to vacuum leaks.
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Old Mar 30, 2011 | 07:09 PM
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Originally Posted by Bonefishmak
I've felt that way about mine too..but, it does seem to go away after it warms up.
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Old Mar 30, 2011 | 07:41 PM
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Originally Posted by Radioman
If it's a 2010 GS w/MN6 built by Mr. Geise @ Wixom, he may have slipped in a ZR1 cam like he did mine. That would attribute to the rough (cam lopping) idle...
Gotta love that... well, at least some folks would.




D
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Old Mar 30, 2011 | 09:07 PM
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My 2010 GS has idled real rough on cold start-up from day one, as if it has a wild cam installed.

After a few seconds the idle settles down to it's normal lope.

I really don't believe you have reason for concern.

Regards,

GSRANDY
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Old Mar 30, 2011 | 09:27 PM
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Originally Posted by Radioman
If it's a 2010 GS w/MN6 built by Mr. Geise @ Wixom, he may have slipped in a ZR1 cam like he did mine. That would attribute to the rough (cam lopping) idle...
What a great accident.
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Old Apr 1, 2011 | 01:13 PM
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I removed the maf sensor and cleaned it. The idle is a lot smoother. Their were traces of oil film spots on the plastic and on the metal. Thanks for the input
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Old Apr 1, 2011 | 01:23 PM
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Originally Posted by sledmaster
I removed the maf sensor and cleaned it. The idle is a lot smoother. Their were traces of oil film spots on the plastic and on the metal. Thanks for the input
If you have a K&N air filter, someone might've oiled it too much.
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Old Apr 1, 2011 | 01:27 PM
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Originally Posted by Radioman
If it's a 2010 GS w/MN6 built by Mr. Geise @ Wixom, he may have slipped in a ZR1 cam like he did mine. That would attribute to the rough (cam lopping) idle...
He is a sneeky SOB
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Old Apr 2, 2011 | 06:25 AM
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Originally Posted by sledmaster
I removed the maf sensor and cleaned it. The idle is a lot smoother. Their were traces of oil film spots on the plastic and on the metal. Thanks for the input
I'm glad it fixed the problem.
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To Rough idle

Old Apr 2, 2011 | 06:50 AM
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Normal. Every 10 seconds or so these cars will shivver a bit.
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Old Apr 2, 2011 | 11:25 AM
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I remember when you bought a new car it ran smooth then after 500 miles it would get a little shakey. Now the last 3 new cars have been different shake at first smooth out after 500 miles.
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Old Feb 2, 2012 | 07:30 PM
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Default More on C6 LS3 "irregular" idle

Recently bought a 2012 1LT w AT. This simple "bottom of the line" model is perfect for me, and I'm very pleased with it except for one thing.

I can't get used to the rough and low-RPM idle. This idle is best described as "irregular" and it feels like not at all like the "lope" I associate with a high-overlap cam (e.g., an old C1 with a ...097 "Duntov" cam, which had a beautiful lope...but I digress).

My car idles like it has an irregular misfire, but I suspect it is not misfiring (would trigger light, etc.). I can feel the car slightly shudder at irregular intervals. Moreover, I'm astonished at the low RPM at idle. Assuming the tach is reasonably accurate in this range, it reads 500 to 550 RPM at warm idle. Cold idle is also rough and only slightly higher RPM.

I noticed this oddity before I bought the car. Dealer said it's normal and started a couple of other 2012 Corvettes with LS3s to convince me.

Also I've read through lots of prior posts and I know that this subject has been discussed quite a bit. But it seems like some basic questions haven't been answered in a convincing way. So I would appreciate hearing from other LS3 owners and/or general corvette experts on:

1. Is the irregular idle I describe normal?
2. Is 500-550 RPM warm idle speed normal?
3. Has anyone ever got an interesting response from a dealer re C6 LS3 rough idle issue?
4. Perhaps this is esoteric, but what causes the irregular idle I'm describing?
5. Also esoteric: If 500-550 RPM idle is normal (my prior Infiniti G37 coupe idled smoothly at 700 RPM), why does GM set the idle so slow? My guess is maybe it relates to emissions certification and fuel economy rating.
6. If others have had this concern, have they successfully just learned to live with it?

Thanks in advance to all responders.
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