I wonder if others here have the same experience. I notice that the car vibrates quite significantly during the first 10-15 minutes after start up. This vibration can be felt in the seats and in the steering wheel. It still occurs during drives, though not as pronounced. The car also vibrates somewhat at stop lights (this is different from the shaking issue we've discussed elsewhere on the forum). Is this just the nature of the engine, or is this something outside your normal experience with the Sonic? I'm planing an oil change in December and want to make sure I bring up any other issue while I'm at the dealer.
Excessive vibration?
- Thread starter pounamu
- Start date
ColonelPanic
Banned
Mine sometimes has a bit of a twitch at idle when cold, but it goes away once warm. It's always quite smooth while driving...
I rented a 1.4L Cruze and it behaved in a similar fashion to my Sonic.
If you feel yours is excessive, definitely get that checked out.
I rented a 1.4L Cruze and it behaved in a similar fashion to my Sonic.
If you feel yours is excessive, definitely get that checked out.
ahtoxa
New member
I had a brand new auto sonic as a loaner a month ago and it vibrated quite a bit in drive when stopped. I have not driven any other auto sonics to compare. I thought it was excessive
Edit. I remembered that the sonic in question threw a check engine light soon after and I brought it back for another loaner. Don't know what the code was.
Edit. I remembered that the sonic in question threw a check engine light soon after and I brought it back for another loaner. Don't know what the code was.
Swordsmith
242hp/252 ft-lbs BNR EFI
I do not know that this is the cause of your problem, but there have been reports that some AT Sonics are... OK, when you come to a stop, your car is supposed to shift into neutral until you take your foot off the brake. Apparently, some cars are not doing that, or having some other problem specifically related to that. This causes a vibration as the engine fights with the transmission. I'm sure someone else can explain this better, at any rate it seems it is a known issue with a service bulletin, easily fixed by your dealer, under warranty.
ColonelPanic
Banned
Good point, swordsmith.
The neutral idle problem will make the car feel like it is surging when stopped. Mine does this intermittently, thus unfortunately will likely never will be reproducible for the dealer. :sadbanana:
Putting it in manual mode will prevent the neutral idle feature from activating, see if that makes any difference.
The neutral idle problem will make the car feel like it is surging when stopped. Mine does this intermittently, thus unfortunately will likely never will be reproducible for the dealer. :sadbanana:
Putting it in manual mode will prevent the neutral idle feature from activating, see if that makes any difference.
davecerv
New member
I feel my Sonic could be smoother at stop but it is very smooth while driving though. At a stop I don't feel vibration on the steering wheel but on the seats you can feel it. On red lights that I know take forever I just move it to neutral...whatever. I wonder hmmm I'm halfway in 8k miles…how will my sonic feel at a stop at lets say 50k?
SonicBoy24
New member
What is the benefit of shifting into neutral at a light?
Cars have never done that before so I don't understand why all of a sudden engineers think that would be a good idea.
I usually use manual mode anyway.
Cars have never done that before so I don't understand why all of a sudden engineers think that would be a good idea.
I usually use manual mode anyway.
Swordsmith
242hp/252 ft-lbs BNR EFI
An automatic never stops straining to go forward, which is why if you lift your foot off the brake you drift. This means the engine is working under load, which means it's burning more gas than it would if you were idling, which means an engine under no load just barely keeping itself spinning.
In an effort to maximize your mpg, the engineers have decided that shifting you into neutral (which is the same as someone with a manual shifting into neutral or standing on the clutch) is a good idea... and it is. Not a great idea, it won't save buckets of fuel, but it will save a little, every time you're standing still, which means you're raising your "city" mpg, which is the worse of the two.
Trouble is, in the old style automatic, the engine was prepared for the strain of sitting still pushing against the brakes, but your engine thinks you're going to shift into neutral, so it lightens up on the gas... and the load is staying put, because your transmission isn't shifting after all.
Should be free to get it fixed, and should only take a few minutes. They shouldn't have to get it to show up on a diagnostic, as there's a service bulletin on it and there's a fix that they just flash in. Cheaper to take your word that you have the problem and apply the fix than it is to keep having you haul the car in, they spend a couple hours trying to diagnose a problem that only shows up intermittently, you take it home unfixed and then bring it back.
At least that's my theory. I am often surprised by the attitude of service departments though.
In an effort to maximize your mpg, the engineers have decided that shifting you into neutral (which is the same as someone with a manual shifting into neutral or standing on the clutch) is a good idea... and it is. Not a great idea, it won't save buckets of fuel, but it will save a little, every time you're standing still, which means you're raising your "city" mpg, which is the worse of the two.
Trouble is, in the old style automatic, the engine was prepared for the strain of sitting still pushing against the brakes, but your engine thinks you're going to shift into neutral, so it lightens up on the gas... and the load is staying put, because your transmission isn't shifting after all.
Should be free to get it fixed, and should only take a few minutes. They shouldn't have to get it to show up on a diagnostic, as there's a service bulletin on it and there's a fix that they just flash in. Cheaper to take your word that you have the problem and apply the fix than it is to keep having you haul the car in, they spend a couple hours trying to diagnose a problem that only shows up intermittently, you take it home unfixed and then bring it back.
At least that's my theory. I am often surprised by the attitude of service departments though.
Just got back from the dealer. Told him about both problems (vibration and shaking) and the solutions that were suggested on the forum. They checked and "couldn't replicate the problem". The plugs were fine (though they did take them out completely to make sure). The car drove fine on the way home, though that was mostly on the highway, which is NOT where my issue is. I'm going to monitor the car over the next few days and see what happens. If the issue persists, I'll contact the Chevy customer service rep from this forum and arrange for one of their people to be present next time.
I'm also thinking, I'm going to learn the manual mode on the car. Won't hurt. Also wondering if this neutral issue is contributing to my low mpg (only 24, though I've only had the car for 2 months). My average speed is 15 mph though, which means a lot of stopping at traffic lights. Still, would be nice to see a higher mpg number.
I'm also thinking, I'm going to learn the manual mode on the car. Won't hurt. Also wondering if this neutral issue is contributing to my low mpg (only 24, though I've only had the car for 2 months). My average speed is 15 mph though, which means a lot of stopping at traffic lights. Still, would be nice to see a higher mpg number.
Chevrolet Customer Care
New member
Hey pounamu,
I'm sorry to hear that you are experiencing a vibration issue with your Sonic. I know you mentioned possibly reaching out to us.We would be happy to look into your situation for you. If you would like our assistance private message us your full name and contact information, VIN, current mileage, and involved dealership.
Sincerely,
Jonathan A.
Chevrolet Customer Care
