Grandpa

Hello all, my 2012 Impala started acting weird a few days ago. What is happening is this: After stopping say at a stop sign, then beginning to accelerate away again, there is what my wife calls a hesitation. To me it feels like a slippage like one of the driving wheels is on ice (but it is summer, no ice) this slippage or hesitation lasts about half a second then it grabs and away we go. Once driving everything seems to work fine, no problems with acceleration or deceleration and the transmission shifts correctly. There are no trouble codes coming up, at least as much as I can tell. Has anyone else had this type of problem, or can someone give any input as to what the problem might be? I am wondering if the torque converter could somehow be loosing it's prime when the vehicle stops, or is that even possible?
Thanks for any input, Grandpa

sledge.impy

Is your throttle body blade sticking? Or is the wire that control it sticking?

Are your rpms increasing when you immediately step on the gas from a stop? Or does it go when it finally jumps?

You could apply the brake - give it some gas, watch the rpms climb, and then let go of the brake and see if it goes some what as expected?

(Holding the brake for a long time while giving gas isn't a good idea in the long run).

Well these are just some ideas.

Grandpa

Thank You sledge for your reply and input, I took the car for a quick run this morning after reading your comments. I watched the tac at every stop and start but wouldn't you know, everything worked fine (no hesitation) I will continue to monitor on future trips and if the problem shows up again, and is as you suggested I'll let you know.
Thanks again for your input.
Grandpa

Grandpa

Hello sledge, I had the car out a number of times today and the problem is still there. I don't believe it is the throttle as you suggested, the tac goes up as it should under acceleration, however I did notice the traction control light flashes when this happens indicating wheel spin, but the pavement is dry and the tire pressures are correct. It sound like it could be a problem with the trac. control system. I think I might have to bite the bullet and take it to the dealer to have it checked out.
Grandpa

sledge.impy

Are your brake pads releasing?

Grandpa

I took the Impala to the service shop a few days ago, the service manager took it for a short drive, and it was on it's best behavior, no problem noticed. They hooked up their scanners and found no engine codes, no transmission codes and no trac control codes. So basically they said drive it till it gets worse, then if we cannot find trouble codes we will do a front end inspection. It seems now when it does the hesitation thing it makes kind of a growling sound, but very subdued, and difficult to pinpoint where it is coming from.
Today I am going to put it up on blocks and have a real good look at the suspension and brakes, both front and back. Hope I can find something simple to fix.
Grandpa

Grandpa

To anyone who has been reading this saga, I jacked and blocked the car up one wheel at a time starting at the right rear, a helper started the car and after applying and releasing the brakes numerous times, the wheel turned freely each time, same for the left rear wheel. The left front was the same but when I rotated the wheel there was a slight clicking sound coming from the cv joint area. I removed the wheel and was unable to see anything out of the ordinary. The right hand wheel, same scenario, but when I removed the wheel I was looking at the lower right rear motor mount. As I looked I thought could this be lifting under torque and giving me a slip and go feeling? With a crowbar and block I was able to lift the engine about 3/4" of an inch, to me that is not normal, but I really do not know. Has anyone had motor mount problems, and should this mount be replaced?
Thanks, Grandpa

infinitelyknown

Just purchased a 2011 LTZ, same problem, more apparent for me when i come out of park into drive. Hestitation for a second then kicks in. No check engine light. Took to the dealership since im thinking the powertrain is covered 5/100,00, i only have 90,000. Took it in and they tell me a code was stored for pressure control sensor in trans and guess what that is not covered and they want $1,200 to repair!!??? Not covered I said, but it's in the trans and they said but it's a sensor and sensors are not covered! Not a bad issue, but it is noticable. Gonna try to appeal to GM to have it repaired, If not, I have an extended warranty, I'll will go through them to get it repaired.

djames

My 2013 was doing the same thing, until i took the rsa's off and bought a set of cooper cs5's,,,,,just a thought..........i'm sure you can go with your favorite tires as long as they are not like the rsa tires...........if you already have bought new tires and still have the problem,,,,i have no ideas..........