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Rough idle/vibration/normal?
Thread Starter
Safety Car
Joined: Mar 2006
Posts: 4,538
Likes: 5,127
From: Chester VA
Rough idle/vibration/normal?
We've had our 2015 Z51 only since last Friday. 8-speed automatic; it's a great car - we love it. At idle (600-700 rpm) there's a slight shake to the car from the engine. I don't know enough about the car to know if that's normal or not. The car has only 13,000 miles, so I'm ruling out any high mileage condition. So is what I'm attempting to describe normal?
TIA,
Larry
TIA,
Larry
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Yes, a slightly rough idle is perfectly normal. Been that way since at least the C5 generation.
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This is exactly the case. GM built the gentle lope into the idle to push enthusiasts' buttons.
The gentle irony is the idle is actually so smooth anyone who has driven or even sat in a car with a serious cam will not even vaguely notice a stock C7's idle. The C7 idle "shakes" only in reference to a buttery smooth BMW or Cadillac.
The gentle irony is the idle is actually so smooth anyone who has driven or even sat in a car with a serious cam will not even vaguely notice a stock C7's idle. The C7 idle "shakes" only in reference to a buttery smooth BMW or Cadillac.
Team Owner
Joined: Sep 2010
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We've had our 2015 Z51 only since last Friday. 8-speed automatic; it's a great car - we love it. At idle (600-700 rpm) there's a slight shake to the car from the engine. I don't know enough about the car to know if that's normal or not. The car has only 13,000 miles, so I'm ruling out any high mileage condition. So is what I'm attempting to describe normal?
TIA,
Larry
TIA,
Larry
Yes, they shake/vibrate @ idle. One thing that may smooth it out is adding a bottle of Techron to a 12 gallon fill from near empty. Do this 3X a year.
Team Owner
Joined: Sep 2010
Posts: 32,042
Likes: 4,610
This is exactly the case. GM built the gentle lope into the idle to push enthusiasts' buttons.
The gentle irony is the idle is actually so smooth anyone who has driven or even sat in a car with a serious cam will not even vaguely notice a stock C7's idle. The C7 idle "shakes" only in reference to a buttery smooth BMW or Cadillac.
The gentle irony is the idle is actually so smooth anyone who has driven or even sat in a car with a serious cam will not even vaguely notice a stock C7's idle. The C7 idle "shakes" only in reference to a buttery smooth BMW or Cadillac.
Links to your claim?
Thread Starter
Safety Car
Joined: Mar 2006
Posts: 4,538
Likes: 5,127
From: Chester VA
Take it to a Chevrolet dealer and have it checked out. You have no idea how the car was driven in the preceeding 13K miles.
Yes, they shake/vibrate @ idle. One thing that may smooth it out is adding a bottle of Techron to a 12 gallon fill from near empty. Do this 3X a year.
Yes, they shake/vibrate @ idle. One thing that may smooth it out is adding a bottle of Techron to a 12 gallon fill from near empty. Do this 3X a year.
Melting Slicks
Joined: Dec 2017
Posts: 2,012
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From: Central Commiefornia
Some say the LT1's shaking is an improvement over the thrashing machine noise of an old school small block with a Duntov 30-30 cam where the solid lifter valve lash was set to .030 inches, creating a clattering that announced the car's arrival well in advance... 
Dunno... sounds sweet to me!
Dunno... sounds sweet to me!Last edited by jimmbbo; Dec 18, 2021 at 06:41 PM.
Pro
Joined: Mar 2014
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I have a Tues AM appt at the local Chevy store for a check up, not so much for this though I will ask about it, but rather to have them look for any issues that should be covered by CarMax's 30 day warranty. If they find something wrong, CarMax will fix it. After the 30 days are up, I've purchased CarMax's extended warranty (60 months) with a $300 deductible that I'll use in the event of any $$$$ repairs.
Thread Starter
Safety Car
Joined: Mar 2006
Posts: 4,538
Likes: 5,127
From: Chester VA
If you're at the dealer and they have another C7 on the lot and are willing to start it up for you, you could compare your idle "shake" to the C7 on the lot. I also have the idle shake and rumble. I took the Ron Fellows owner's class and every C7 I drove there also had the slight idle shake. I enjoy the rumble at idle, part of the car's character, just like the cold start sound.
