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Cylinder 3 Misfire and Service Traction

49K views 33 replies 4 participants last post by  ChevyCustSvc 
#1 · (Edited)
I've been having an issue for quite some time now, and have yet to find the solution. I've searched everywhere on here and the net in general trying to find a fix to these issues.

My car runs rough at idle, but smooth when up to speed. There is a CEL that came up as a cylinder 3 misfire. The Service Traction light also comes on and the vehicle shifts hard from first to second, and sometimes from second to third. Again, when the car gets up to speed, the shifting smooths out.

Here is a list of things I've done, (and approximate cost for those who want to do it themselves).

Cleaned Throttle Body - ~$5
Cleaned MAF Sensor - ~$8
Replaced Spark Plugs - ~$50 (plugs, socket, grease)
Replaced Fuel Injectors - ~$170 and approximately a pint of blood :blink:
Replaced Air Filter - ~$20

The things left on my to-do list are:

Fuel Filter - ~$30-70
Ignition Coils - ~$250 for all four


I think before I order ignition coils, I'm going to get a scanner and move the coils around to see if the misfire follows them. If not, I can rule out the coils.


Any other ideas? I'll keep this thread updated as I keep trying stuff.

EDIT: This is a 2009 with the 2.2
 
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#2 · (Edited)
Is your coolant dropping?
 
#4 ·
Check out the fuel injectors too, they come off easily, just release the pressure from the valve, then remove them and inspect.

Its probably the coil though, if you want, you can pull the coil pack out and remove the boots, then have somebody turn the key several times and watch the coil pack for sparks, usually a trained eye is needed, but you should find out if your coil pack is shot.

If you have used Boshe platinum plus spark plugs consider your coil pack fried as these POS spark plugs will ruin your coil pack. Use ACDelco plugs only, or at least other branded ones that are not so hot, like autolite.
 
#6 ·
I've actually already replaced the injectors - replaced them with AC Delco injectors from rock auto.

I had read that most plugs other than the AC Delco replacements were junk, so I replaced those with the same exact plug.

If I check the coils like you suggest, do I need to pull the fuel relay to keep the fuel pump from flooding the car while there is no spark?

Well then your on the right track with coil pack swap. Let us know if misfire follows coil.
Will do - it will probably be the middle/end of next week because I just ordered a scantool. I've seen multiple threads like this that all address the same/similar problem that I'm having and I haven't found a solution in any of them, so I want to do a complete thread of me tracing the problem and hopefully fixing it.

The car is still under the powertrain warranty, but I know the dealer would want to change all this stuff I'm changing now first. That's why I'm doing it myself to save money (hopefully - may be wasting it for all I know). That's another reason I'm using all the same exact replacement parts.
 
#5 ·
Well then your on the right track with coil pack swap. Let us know if misfire follows coil.
 
#7 ·
If I check the coils like you suggest, do I need to pull the fuel relay to keep the fuel pump from flooding the car while there is no spark?
I would, but its not really required, it would just cause a rough start the next time you start it, but it will burn off and be fine after that.

The best test honestly is to 'borrow' a coil pack from another cobalt that you know is working, if you can borrow one, then test it that way instead, if not, go ahead and do the visual inspection.

Powertrain warranty, that means they should fix this for free, I would simply take it to them to fix, you can probably get a new coil pack, genuine GM one too.
 
#8 ·
Powertrain warranty, that means they should fix this for free, I would simply take it to them to fix, you can probably get a new coil pack, genuine GM one too.
But then you avoid all the fun of trouble shooting.
I would just switch coil with let's say cylinder one and 3, reset code and wait to see if code follows coil to cylinder one. 2 connectors. If it does problem solved. Then you can bring it to GM and have them replace the coil at their cost. At least you get the satisfaction of knowing what was wrong and finding the problem yourself.
 
#9 ·
True, but some don't have as much fun problem solving like us.

I'm assuming you do not have the standard ecotec 2.2 engine, correct?

You do mention switching the coils around, I just don't see how this is possible with the ecotec...
 
#10 ·
You do mention switching the coils around, I just don't see how this is possible with the ecotec...
What do you mean, they sit right on top of the plugs.
 

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#12 ·
Yeah, he never mentions the year of his Cobalt... Always nice when it's in the signature, it helps us help you.
 
#14 ·
Sorry, completely forgot the year - its a 2009 with the 2.2L engine.

I have read that the power train warranty wont cover ignition coils, but it would be great if that's the case and they are the culprit.

What I'm trying to avoid is taking it in, paying 50 bucks for a diagnostics only for them not to fix the issue. Although it may not happen like that, I've read way way way to many stories where it has.

It is also pretty rewarding to solve a problem yourself.
 
#15 ·
I hate Chevy/GM for this

Powertrain means anything that makes your car run, I understand if you complain about your doors not locking or a speaker not working..

But a coil pack is part of the engine and it needs to work correctly for your car to run, they should cover it. Do not get a diagnostic with them, you can get this for free at autozone or advanced auto parts.

Mixing around the coils can help you solve your problem, since the dealership is not helping you, I guess your on your own, you will have to solve this yourself. If you mix the actual wires your engine will not run right, you need to only change the coils, since I do not have the same system as you, I cannot help much, but changing the coils over will help you figure out if its the coils or not. If it is, just replace the offending coil, if not, then post back here.

I strongly suggest you consult someone who knows the law, powertrain warranty should include this, if you need to get a lawyer to say so then so be it.
 
#16 · (Edited)
Thanks for the advice. I ordered a wifi scan tool (OBDLINK) partially because it will help me solve this problem and partially because it will be fun to play on the iPhone and iPad with the dash command software. When I get it next week, I'll post up my findings.

Im lucky enough to have a backup vehicle (although it only gets 13 mpg) so it will be sitting still until I solve the issue.


EDIT: After doing some more reading, the ignition coils are generally not covered under any manufacturer's powertrain warranty because they are an electrical component, not part of the actual engine.
 
#18 ·
Misfire did NOT follow the ignition coil so that isn't the issue. I did notice a hissing sound coming from the right side of the engine. When I cleared the misfire, it went away.

I have a bunch of readings if anything can be helpful.

Timing is around +8 to +12
Intake temp is ~ 90 deg
MAP is ~ 10 inHg
MAF is .5 lb/min
Catalyst is 822 deg
Fuel flow is .4 gal/hr
VAC is ~ -9.5psi
Throttle position is ~ 19%

One quick question - does the cobalt have more than one O2 sensor?

Any other ideas? I'm kinda stuck now.
 
#19 ·
2 Pre-cat and downstream
 
#21 ·
Just bank one HOsensor1 HOsensor2. Unless maybe California might have bank 2.
 
#23 ·
Just go in menu and drag proper item (O2B1S1)to your screen. O2B2S1 should not be there for a Cobalt. Everything else looks normal. Which APP are you using?
 
#24 ·
Dash command. I'm still very new to it. Here is a dump of information that may or may not be useful.

I'm still baffled by the hissing noise that goes away once I clear the misfire code, but comes back with the CEL.

With the risk of sounding like a dumbass, I don't really know anything about this car other than what I've learned changing the plugs, injectors, and cleaning the MAF and throttle body.



---------- Post added at 06:01 PM ---------- Previous post was at 04:27 PM ----------

More info - when the car is at idle, it says "Fuel System 1 Status - OL - Fault". When I press the gas, it changes to "Fuel System 1 Status - CL".
 
#25 · (Edited)
OL I think stands for Open Loop and CL for Closed Loop.

The only thing I find a little odd is your battery voltage that to me seems high. 14.3V would be normal but that 15Volt is defenitely too high. Don't know if it has anything to do with your misfire but I would check that with a good Volt meter just to be sure your alternator is not over charging and maybe playing tricks with your ECM.

---------- Post added at 11:27 PM ---------- Previous post was at 11:23 PM ----------

I notice that both HO2 sensors are in the log and reading fine.

Are these reading from the same OBDII diagnostic program?
 
#27 ·
Right at the battery while car is running from post to post. It should read very close to 14.3Volts.

---------- Post added at 12:22 AM ---------- Previous post was at 12:18 AM ----------

What kind of gas are you burning?
 
#30 ·
Oh no! That's to bad!

Yep! Sarah could probably verify for you if you PM her your VIN
 
#31 ·
Just sent Sarah a pm - hopefully she can help me get the problem taken care of. She always seems to be very helpful!

Wonder what would cause this after only 75k miles. I drive about 85% highway at constant speeds around 65 - 75 with the cruise normally on. I have no mods on the car either.
 
#32 ·
Might be a head gasket.
 
#33 ·
Verdict is in from the dealer - need a new cylinder head. They said the parts should be in tomorrow and they hope to have it to me by the end of the day. Everything will be covered under the powertrain warranty!

I want to thank Sarah for assisting me in the process of getting this taken care of!
 
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