Shaking when starting, possible misfire

[Mitoni]

I just joined the forums to see if anyone else has had this issue, or if they know the cause before i take it in to the dealer today.

I started my car last night, and it was a cold start, and cooler outside than usual (49 degrees in Orlando, FL) and all of a sudden, the car began shaking so violently that a) the stabilitrak began flashing and b) the car felt like it was going to stall out from the force of it. It was sitting in park in my driveway. I turned it off and waited a few second, turned it back on, and now my engine light is on solid. before it was flashing when this problem occurred.

It feels like it may have been a misfire, and even after that, I had to drive to pickup my wife, and it feels like it may be idling rough.

Any ideas?

 

[Natesriv]

Hello and sorry for your problem.

Is it the 1.8 or 1.4 liter engine?

Is your OnStar still working? They can diagnose the more simpler trouble codes and perhaps give you an idea.

Sure sounds like a bad coil or something in that area...

Guys?

 

[Chevrolet Customer Care]

Mitoni,

Welcome to the forum! Sorry to hear that you're having issues with your Sonic. Hopefully the dealership will be able to determine what the cause is. Be sure to keep us updated.

Vanessa
GM Customer Service

 

[Mitoni]

Onstar confirmed a misfire. Just at the dealer now.


XD(m) .45 3.8" bi-tone

 

[Papasonic]

I had a similar problem with my 1.4 LTZ. The ignition coil pack failed to fire #4 cylinder, causing the same symptoms as you have described. A new coil pack assembly fixed the problem.

 

[GeneralZod]

Coil pack all the way. Another weak area that spans the car maker universe. I bet moisture got in there...

 

[Mitoni]

So code confirmed the misfire, but could be several causes, and considering I'm driving 4000 miles next week, they didn't want to have it happen again mid-trip.

So I got a Cruze for now, and they are diagnosing it more. Also while they have it, there is a recall on the front suspension (sway-arm bolts I think they said), and one if my driver side backup bulb went again, so it's getting a new harness, and I'll toss my oil change onto the list just to get it out of the way.

So hopefully they can get it figured out in 5 days, since I leave Orlando headed for New York and Canada 4am Wednesday morning.

 

[sx sonic]

Hope they get it fixed for you in time. Sounds like they're takeing care of ya.

 

[HADES20]

Mine shook once when it was cold a couple weeks after he came home but hasn't since

 

[Mitoni]

Mine shook once when it was cold a couple weeks after he came home but hasn't since

I thought the same but they said cold wouldn't cause a misfire.

 

[Mitoni]

So I called and got an update this morning. They cleared the codes and tried to get the check engine light to come on again with about 15 miles of test driving, which it didn't. It did however record roughly 200 misfires in that time. So they are driving it more tonite (service manager lives a good distance away, and he will drive it home) to try to get the code to pop again.

 

[Chevrolet Customer Care]

Mitoni,

Hopefully it's nothing major and they get it figured out. Thanks for the updates!

Vanessa
GM Customer Service

 

[dvn]

So I called and got an update this morning. They cleared the codes and tried to get the check engine light to come on again with about 15 miles of test driving, which it didn't. It did however record roughly 200 misfires in that time. So they are driving it more tonite (service manager lives a good distance away, and he will drive it home) to try to get the code to pop again.

Mine did the same thing one time. Has not done it since. It will occasionally idle a bit rough on start-up but no CEL or stabilitrak light.

 

[Mitoni]

I called today. They still haven't gotten it to pop the check engine again, but they did have another Sonic come in having the same problem. They are calling TAC on Monday. I hope they can figure out the problem, then get it fixed in 24 hours. Otherwise GM customer service is going to have to figure out how I can take a loaner on a 4500 mile road trip to Canada. Considering my mom is a GM warranty administrator, I know how big a request that would be.

 

[Papasonic]

I wonder why the techs just didn't use the information provided by the codes already set to make a diagnosis. At some point they will have to make a decision to do something; even if it's wrong. Continuing to just drive around to wish for more codes to appear is futile. They already determined there is a continuing missfire. Either the missfire is related to a fuel system, an ignition system problem, a compression problem, or a vacuum leak problem. Techs, just pick one: No more joy rides!

 

[Mitoni]

I wonder why the techs just didn't use the information provided by the codes already set to make a diagnosis. At some point they will have to make a decision to do something; even if it's wrong. Continuing to just drive around to wish for more codes to appear is futile. They already determined there is a continuing missfire. Either the missfire is related to a fuel system, an ignition system problem, a compression problem, or a vacuum leak problem. Techs, just pick one: No more joy rides!

The problem was, the code that came up was a generic misfire code. It did not provide enough info to properly identify which of a dozen or so components can cause the same problem. And since GM eats the cost of this since its warranty, they don't want to waste any.

I'm sure if I was paying for it myself, they would be replacing parts left and right on my dollar.

 

[GeneralZod]

Ok, but like Papa said, it can only be a set of issues. They aren't looking at a data log in the shop or on the road. Instead, they are doing the poor man's style like we would. Wait for a code to identify the issue.

My problem with that, it lacks professionalism and logic. You also have a tech driving your car around misfiring. If it is misfiring and driven other problems can arise. Oil, O2 sensors, and catalytic system are being compromised.

Maybe Papa can chime in if I am way off base. However, I think the fact they don't want to look at logs shows one of two things, they do not have the skill or do not want to spend the time. Either way, they are not backing their product.

They have a choice, fix it or give you a car for your trip. It is not your problem, period.

 

[Papasonic]

GeneralZod,
I agree with your post. The technician should use the retrieved data already recovered; then use this information to further isolate the defect. This includes visual inspections, individual component testing, and sometimes substituting known good components. The retrieved data will not say to the tech; "change this component", it only will tell the tech what systems potentially are responsible for the fault, and what parameters are not within specification. From there the tech needs to exercise some problem solving skills, expertise, and some common sense.
Driving a vehicle with a misfire can indeed cause damage to the emission system. When my coil failed, I was instructed by an OnStar representative to not operate the vehicle until the misfire was corrected; thus a tow to the dealer was provided.
If the techs are waiting for a magic code to appear, and tell them precisely what to do; that's not happening!

 

[Mitoni]

GeneralZod,
I agree with your post. The technician should use the retrieved data already recovered; then use this information to further isolate the defect. This includes visual inspections, individual component testing, and sometimes substituting known good components. The retrieved data will not say to the tech; "change this component", it only will tell the tech what systems potentially are responsible for the fault, and what parameters are not within specification. From there the tech needs to exercise some problem solving skills, expertise, and some common sense.
Driving a vehicle with a misfire can indeed cause damage to the emission system. When my coil failed, I was instructed by an OnStar representative to not operate the vehicle until the misfire was corrected; thus a tow to the dealer was provided.
If the techs are waiting for a magic code to appear, and tell them precisely what to do; that's not happening!

I hear you. Im also surprised they didnt call TAC sooner. now, we are stuck waiting til Monday to call TAC, and then once they have the problem diagnosed by them, that only leaves 24 hours to get parts, get it fixed, and get it back to me by Tuesday night. I need to leave by 5am Wednesday morning, come hell or high water, or my entire itinerary is blown for the trip.

 

[GeneralZod]

I hear you. Im also surprised they didnt call TAC sooner. now, we are stuck waiting til Monday to call TAC, and then once they have the problem diagnosed by them, that only leaves 24 hours to get parts, get it fixed, and get it back to me by Tuesday night. I need to leave by 5am Wednesday morning, come hell or high water, or my entire itinerary is blown for the trip.

This is where their foolishness requires creative thinking. Something that has not been common in the last 10 or so years in the car industry across the board.

Like I said, with their foolishness, if a part requires a long turn around. Pulling a part off another vehicle in the lot wouldn't be a bad idea. Hack, yes, but still showing they care about your car and situation. Then throw in an oil change or two, and you leave feeling like a friend just did you a solid. Sure they could say this violates SOP or some other tripe. But when aren't dealerships doing shady things?

Remember this, while you are not paying for this service GM is. Having a car sit with apes floating question marks is bad. Same reason GM has people here. To right the ship. You are posting this and others are reading it. I think their goal should be to get you out and smiling.

I had to deal with VW dealerships for seven years. I left them for that fact alone, and went back to GM. Just because the Cadillac dealership by me serviced things with me asking. It went in with a minor dashboard glitch and left with a rebuilt transfer case and rear end. They said while testing the dash the tech heard a slight whine, which develops into failure. They were going by past experience. The Chevy dealer by me is not as proactive but close. I suggest you find one, they are out there.

Sorry about the ramble, I have been where you are... Just a tad worse with the result.