Engine/auto shift question

[MrBlack]

Ok I'm going to attempt to describe this the best I can. I don't know if its supposed to drive like this or not:
Engine: 1.8L Auto
Trim: 2LT
When I'm driving and the sonic shifts up there seems to be either a slight lag, or almost like its working really hard, on level road. And when I'm going down a steep hill and I let off the gas it feels like I have the brakes on slightly, but if I shift it into neutral it feels like it coasts more freely.

Let me know if this is to be expected or I'm just paranoid, or what. Keep in mind the newest car I've ever driven was an 07 Chrysler Town and Country.

 

[Sonic]

I'm going to go out on a limb and say that you are feeling the normal workings of the 6 speed tranny? I'm not an "auto" person or guru, is the 6at in the Sonic cvt? That would explain the feeling that it's hunting. Plus, you are going from a 3 or 3.5 maybe 3.7(?) liter engine in your van to a 1.8 in your Sonic, so that is going to contribute as well. Again, just my guess on the tranny, since I don't know the automatic world too well.

 

[2>4]

...is the 6at in the Sonic cvt?

No, it's a 6 speed automatic, with 6 discrete gear ratios.

A CVT (Constantly Variable Transmission) uses belts (or chains) and adjustable-diameter pulleys to continuously change the gear ratio. When you hit the gas, the engine accelerates to the rpm where it produces peak horsepower, then holds there while the transmission continuously adjusts to maintain acceleration. So instead of the usual sound of the engine repeatedly winding up/pausing to shift/winding up you just get a continuous BWAAAAAAAAAAA exhaust note while the car changes speeds. It's definitely a weird sensation if you've had a lifetime of experience with conventional transmissions.

 

[Sonic]

Ok, so I'm going to go with the difference and sensation the OP is feeling just being the fact that it's a 1.8 engine and a new and completely differently geared (in relation to his old vehicle's) 6 speed transmission trying to find the optimal gear.

 

[MrBlack]

That doesnt explain the down hill sensation, does it?

 

[Sonic]

That doesnt explain the down hill sensation, does it?

Uh, because even if you let off the gas the transmission is still "in" a gear and you have actually started the process of tranny braking/engine braking the car??? That would give you the sensation that it is "braking" or "slowing down". The car isn't going to select neutral on its own.

And putting it in neutral would actually be letting it "free wheel" and could actually lead to acceleration if on a steep enough hill.

 

[TravsSonic]

I've never driven a AT that felt like it was getting engine braking going down hill. every auto i've ever driven required braking because they were freewheeling in that situation.

And if you feel like its laboring, then it probably is, especially if you feel something isn't shifting perfect. Keep an eye on it, listen for anything out of place.

These aren't the most reliable transmissions. Hope its nothing serious, but when it comes to AT's.. i'm probably the least positive person you would ever meet.

 

[Sonic]

This should be in transmission discussion forum.

 

[speedog]

My 1.8l 2LT with the auto also feels like it's engine braking when you let off the gas - first time I've experienced this and I've been driving a variety of Chev's with auto's for over 30 years now. Not a big deal and actually in stop and go type of traffic, it is kind of convenient - has to be noted that this is the first small displacement Chev I've owned (and lightest) and the first with an auto with more then four forward gears - could be just in the design of the tranny.

 

[BoG233]

Same here

I swear it feels like Turbo lag it a little dangerous in tight traffic . I feel it more as I come almost to a stop but not quite then go to take off . The engine will tack up to about 4 1/2 grand without even moving . Scared the crap out of me and my wife the first couple of times it happened . Now I know what to expect . It will happen at any speed slow down like to stop and don't stop take off and it will rev wildly .

 

[Sonic]

Which is why I always get a manual. I prefer to choose my own gear instead of having "Skynet" choose it for me!

 

[TravsSonic]

I swear it feels like Turbo lag it a little dangerous in tight traffic . I feel it more as I come almost to a stop but not quite then go to take off . The engine will tack up to about 4 1/2 grand without even moving . Scared the crap out of me and my wife the first couple of times it happened . Now I know what to expect . It will happen at any speed slow down like to stop and don't stop take off and it will rev wildly .

this is a known problem/complaint from the cruzetalk forum, the AT will leave you sitting at a light or intersection reving the engine trying to get it to move.

mmmm... love my MT!!

 

[SethV]

Ok I'm going to attempt to describe this the best I can. I don't know if its supposed to drive like this or not:
Engine: 1.8L Auto
Trim: 2LT
And when I'm going down a steep hill and I let off the gas it feels like I have the brakes on slightly, but if I shift it into neutral it feels like it coasts more freely.

There is a feature called DFCO, or Deacceleration Fuel Cut Off. With the Sonic 1.8 AT, when you lift your foot off the gas and coast, it actually shuts the fuel off to the engine. This is a small fuel ecconomy enabler. It does feel a bit different than older cars that don't have this since the momentum of the car actually keeps the engine spinning and the car feels like it has more "drag". When you need power again, the injectors once again open and since the engine is still spinning it "starts" again without you ever knowing the difference.

Hope this helps explain what you feel, it is your Sonic saving you some $$.

 

[BoG233]

this is a known problem/complaint from the cruzetalk forum, the AT will leave you sitting at a light or intersection reving the engine trying to get it to move.

mmmm... love my MT!!

I love a manual Transmission but the wife and her bad hip can't drive them any more .

 

[TravsSonic]

I love a manual Transmission but the wife and her bad hip can't drive them any more .

now THAT is a valid reason to buy a AT!!! If someone is physically limited and can't repeatedly push in a clutch you won't hear me fuss.