misfire happening in my camaro

[greg_tolson]

I have a 2011 v6 camaro with a K&N typhoon cold air intake and an MRT v2 exhaust. I currently have 37,500 miles and had a fuel injection cleaning 2 months ago. In late november my car had a misfire while I was driving on the highway. I took it to the dealer and they couldn't figure out the problem and just flipped off the CEL and checked all the plugs.

This afternoon my car had the same issue right after I started the car (15 degrees F outside). I restarted the car and the CEL light just stayed on. I was able to drive home with no issues and it felt fine (I set up an appointment with a different dealer on Friday afternoon)

I am wondering does my cold air intake have anything to do with this? The MAF is installed and doesn't look like any wires are loose. Does the cold air have anything in conjunction with the cold air intake affect any readings? Was hoping someone could help me out.

[Nutbutt]

A lot of V6s have been having issues with winter blend gas. Run a couple cans of gas treatment. Just use a quality treatment like the GM or Royal Purple type.

[TooCool5]

Originally Posted by Nutbutt

A lot of V6s have been having issues with winter blend gas. Run a couple cans of gas treatment. Just use a quality treatment like the GM or Royal Purple type.

^^This^^
I had misfires also at 17 deg. cold starts, had to run dry gas and fuel treatment and it cured it, although still a rough start when cold out.
That was 4 yrs ago.

[Nutbutt]

Just came back from my local Chevy dealership picking up a 2014 PCV. There were 4 V6 camaros in the bays getting serviced for misfires. Parts manager said since November they have been at least 2 or 3 a week for fuel treatment and upper induction cleanings. He said most respond to the fuel treatment when done on two consecutive fillups. They seem to believe it is a combination of the winter grade fuel being processed and the extreme cold. Funny it seems to be more prevalent to the V6 LLT and LFX ???
Anyway it surely is good biz for the dealership.

['11CamaroLS]

Does the GM upper induction cleaning work well? Is it as good as seafoaming your engine?

[greg_tolson]

Thanks for the help, I'll try filling in some fuel treatment this afternoon (does sunoco carry the good brands?) Also to go in depth on my last visit to the dealer back in late Novemeber. I remember they moved the coil packs around to test and see if the coil that was in the misfired cylinder would misfire in another cylinder which it didn't. So a bad coil had been ruled out; they also made sure the rest of the coils were connected properly.I had the fuel injection cleaning literally 1-2 weeks before this problem happened which I paid 120$ for, not sure how good GM's fuel injection cleanings are (I was in getting only an oil change and I was an indiot and said sure to the fuel injection cleaning).I have started my car in weather that was in the single digits (probably 2 weeks ago) and it was fine. It's weird it happened when it was only 15 degrees out.

[Nutbutt]

Originally Posted by '11CamaroLS

Does the GM upper induction cleaning work well? Is it as good as seafoaming your engine?

Depends on who does it. I have seem some dealerships take apart the IM to clean. Then I have seen them just ingest by the break booster vacuum. A good seafoam should include brake booster and insert though the IM inlet to get all cylinders.
Best is to start with a seafoam and royal purple type gas treatment.
If no improvement after a few tanks fulls. Move on to a IM removal and cleaning by you or dealer.

[TooCool5]

Somehow the intakes hang up in the extreme cold.

[Eddiefuzz]

Catch Can, Catch Can, Catch Can. BTW you don't need to remove the whole intake manifold to clean it, you can take the cover off. I know people will say take it to the dealer for a "Top End Cleaning", that's a couple hundred bucks. I take the cover off and wipe down the inside, I have a catch can so it's not so oily any more. I also spray Sea Foam down the intake ports, not much just a few sprays each with the straw, let it sit as I wipe out the manifold. Put it back together, then do the Sea Foam as directed on the can. Aerosol Sea Foam, there are two kinds. I use STP for the engine oil just before I change the oil, it's way cheaper than liquid Sea Foam. EAZY PEAZY!

[greg_tolson]

Well the dealer threw in a new spark plug for the cylinder that misfired (cylinder 1). A week later I had the misfire at cold start again (in the past two gas fill ups ive been putting in gas treatment). The car runs so smooth when its warmed up (or when I start it in my semi warm garage) but it keeps misfiring when I leave it outside (constantly been under 30F here) for extended periods of time. When I turn it on itll rev above 1 rpm like it always does but as it makes the transition when its warmed up thats when it misfires. I also have noticed the car will sometimes start roughlly with like a pop sound or itll rev much higher than 1 rpm for a few seconds and then come back down. I took it back to the dealer and they let it sit out over night outside and are starting it this morning to hopefully find the source. Another weird symptom I've gotten from the car probably within the past 6 months or so is when my car shifts (either between 3-4 gear or 4-5 gear cant remember) itll sometimes down shift really quickly then upshift twice (i have an automatic). anyone have something weird like that happen to them once in a while?

[Nutbutt]

What you are seeing, misfires during cold start at cold temperatures seems to be a problem effecting many v6 and v8. Dealers are blaming the winter fuel blend, possible oil ingestion through intake manifold and of course really cold temperatures. Was -11f this morning but I did not even attempt to start the camaro. Honestly I don't think they will really find any problems. Changing plugs is not the answer these plugs are really bullet proof.

[BlackoutLFX]

-14 degrees coolant temp. is when alot of the computer control systems switch on. They ramp up from there slowly becoming more aggressive with coolant temp raise. Probably just a hiccup because of the cold temps.

[BlackoutLFX]

Originally Posted by greg_tolson

Well the dealer threw in a new spark plug for the cylinder that misfired (cylinder 1). A week later I had the misfire at cold start again (in the past two gas fill ups ive been putting in gas treatment). The car runs so smooth when its warmed up (or when I start it in my semi warm garage) but it keeps misfiring when I leave it outside (constantly been under 30F here) for extended periods of time. When I turn it on itll rev above 1 rpm like it always does but as it makes the transition when its warmed up thats when it misfires. I also have noticed the car will sometimes start roughlly with like a pop sound or itll rev much higher than 1 rpm for a few seconds and then come back down. I took it back to the dealer and they let it sit out over night outside and are starting it this morning to hopefully find the source. Another weird symptom I've gotten from the car probably within the past 6 months or so is when my car shifts (either between 3-4 gear or 4-5 gear cant remember) itll sometimes down shift really quickly then upshift twice (i have an automatic). anyone have something weird like that happen to them once in a while?

Check your speedometer reading and approximate pedal position when the problem occurs. Probably in the 30-60 mile per hour range going up a slight grade with less than 40 percent throttle. Sounds like the torque converter clutch is locking up and you are feeling it. I have it tuned out in my transmission at the expense of a little gas mileage. Since I have a transmission tune the converter is set to lock up more aggressively and it annoyed me. It felt like a 4-3 downshift when it locked up. I just set the lock up speeds a litter higher to tune it out......Probably operating the way it is supposed to.

[AKA-22]

http://www.camaro5.com/forums/showth...08#post7408408