2007 Cobalt, Idling violently, Video inside

[Hellotalkie]

My friend's 07 cobalt has the check engine light on. Tried to read it with my scan gauge, came up with B2AAA and B2A00

I'm assuming my reader couldn't read the codes.

Anyways when you turn on the car, the rpms go from 1 to 2k constantly, back and forth.
I have a video of the engine bay doing this.

http://www.youtube.com/watch?v=g55-qrpfEHk

RPM view
http://www.youtube.com/watch?v=C6f8ctFUyPQ

Car only has 34xxx miles
On original spark plugs, said the fuel injectors were cleaned

 

[c3p0]

Vacuum leak maybe? Could be fuel injector related as well. Hell, it could be many things I guess.

c3p0

 

[DivideBYZero]

I'm going to say MAF sensor.

 

[OILFIELDTRASH]

I had a neon that did some crazy stuff like that about 40k miles and they tuned it up and replaced the plugs and it went away. The whole car would shake like someone was jumping on it. My mom currently drives it with 90,000 miles on it and no issues.

I'd tow that thing to the dealership personally. Vibration that bad could f up the motor mounts.

 

[Hellotalkie]

Do you suggest changing the plugs? That's something I can do.

 

[OILFIELDTRASH]

I'm no expert but that is one of the things they said they did for the neon I had. I think they did new wires too. It was about 7 years ago so I don't remember exact details.

 

[Arkaign]

Replacing the plugs and checking the wires and contacts is a wise and cheap move at this point. There are many potential causes of something like this, but that's an easy one.

 

[SuperSix]

Idle speed solenoid/control could have take a crap - check the basics first though, plug wires, vacuum leaks, etc.

 

[EightySix Four]

Running on 3 cylinders, check plugs, coils, and fuel injectors first.

 

[thescreensavers]

So whats the engine light say?

 

[BUTCH1]

Wait until dark, start engine and look for any arcing, plugs should not be an issue at that mileage but one might have gone bad and it's cheap enough to change 'em. How is the air filter, still the original?

 

[Vette73]

Pull the engine code first and chances are the answer will be a easy one. Don;t go replacing parts without at least the basic engine code first.
i.e. like Cyl X misfire, MAF reading..., etc...

Also I think the 07 Cobalt is a CAN bus. So make sure the OBD2 reader is a newwer model.

 

[LTC8K6]

Yeah, if the CEL is on, then get the code read first.

 

[Lotheron]

I would definitely just run some injector cleaner first. Surprisingly enough I had the same thing happen at 45K miles on my equinox. I would not have thought it would have been that dirty already, but it was.

 

[CraigRT]

Last time I saw an engine shake like that it was when my Saturn had a coil go bad. It was running on 3 cylinders. Replaced the whole control module and coils from a wrecker car, and smooth as silk afterwards.

 

[5150MyU]

B codes are for the body control module: interior lamps, door switches, instrument cluster, seatbelts , etc.
B codes are B0012, B1045, B3976 --none contain letters such as AAA

 

[EightySix Four]

B codes are for the body control module: interior lamps, door switches, instrument cluster, seatbelts , etc.
B codes are B0012, B1045, B3976 --none contain letters such as AAA

The B2AAA is an error with the reader, not the car. The symptoms say misfire on one of the cylinders, most likely a plug, coil pack, or injector.

 

[brblx]

sound would help. but yeah, it looks like it has a dead miss on one cylinder.

pull the plastic engine cover up and make sure all the coils are plugged in. i've seen those connectors come loose. if that's okay, it's iirc just one 10mm to pull the each coil. pull the boots back and inspect for cracks, pull the plugs out and inspect them too. that's the easiest and most common stuff to look at. past that you def need to pull DTC's before going any further.

if he had some kind of fuel service done, my bet would be on dead/plugged injector or possibly a fouled or damaged plug.