Misfire at 3k rpm, Help!

Azure_King · 10-29-2019, 01:44 PM

So, new to the forum, nice to meet everyone!

I have a 2016 Camaro SS with 57k on the clock; It has a misfire on cylinders 5&8 between 3-4k Rpm.

So far I have replaced all fuel injectors, the fuel pumps and the ignition system(plugs, wires, and coils) this has been an issue since i bought the car a year ago and I’ve taken it to two chevy dealers and they can’t seem to figure out whats wrong.

Recently I reset the torque on all the rocker arms just incase something was too tight and to make sure i didn't have a weak or collapsed lifter...

Any Ideas? Thanks in advance!

P.s. the car is stock aside from long tubes, and a tune.

ssmofo · 10-29-2019, 01:51 PM

I would suspect the tune if you have changed all that, does it bring on the CEL?

Wilka_SS · 10-29-2019, 02:50 PM

Check for a broken valvespring or carbon collected on either of the intake and exhaust valves preventing the valve from seating and sealing.

Azure_King · 10-29-2019, 03:01 PM

@SSMoFo- this has been an ongoing issue since the car was bone stock; CEL flashes but doesn’t stay on.

@Wilka_SS- None of my valve springs appear to be cracked or broken... I’ll have to check throughly for carbon buildup on valves.

sal11585 · 10-30-2019, 09:28 AM

I am no expert , but maybe its something electrical . Maybe the wiring to the coils or something. Especially since its always done it and looking at what you replaced already, I cant think of anything else it could be.

Cechk01 · 10-31-2019, 07:05 AM

it should still be under powertrain warranty, tell the dealer to fix it

Azure_King · 10-31-2019, 07:49 PM

Quote:

Originally Posted by sal11585

I am no expert , but maybe its something electrical . Maybe the wiring to the coils or something. Especially since its always done it and looking at what you replaced already, I cant think of anything else it could be.

Everything looks fine visually... I’ll put a multi meter on the harness this weekend just in case...

Azure_King · 10-31-2019, 07:52 PM

Quote:

Originally Posted by Cechk01

it should still be under powertrain warranty, tell the dealer to fix it

My warranty expired a couple months ago.

However, I have a 3rd party extended warranty that covers what chevy would in their powertrain warranty(all internally lubricated parts, not including injectors).

Gunkk · 10-31-2019, 08:45 PM

Quote:

Originally Posted by Azure_King

My warranty expired a couple months ago.

However, I have a 3rd party extended warranty that covers what chevy would in their powertrain warranty(all internally lubricated parts, not including injectors).

Waitasecond....How is a 5/60 warranty expired already at max 4 years and 57k miles?

Edit: nevermind, I see you have a tune.

Azure_King · 11-01-2019, 05:25 PM

Quote:

Originally Posted by Gunkk

Waitasecond....How is a 5/60 warranty expired already at max 4 years and 57k miles?

Edit: nevermind, I see you have a tune.

Good eye, but my dealer didn’t care about the tune...

Edit: Checked my e-mail again; the notice was to let me know my warranty was expiring soon

Azure_King · 11-02-2019, 08:47 PM

Update: As of right now there is no more misfire, we’ll see what happens when I take her back to the dyno...

Things I did: checked all wiring from the ECM to each coil(no issues found), checked all ECM fuses and relays(no issues found), Replaced all pushrods and re-gapped spark plugs from .040 to .035.

Thanks for the input guys!

Azure_King · 02-06-2020, 09:59 PM

Update: Maybe I can save someone a headache later down the line

So, the misfire came back a few weeks after the aforementioned parts were replaced

So, I took my time and diagnosed a little better....
Misfire only happened at 3k or higher steady state throttle.

I already ruled out the ignition system, fuel system, and the possibility of damaged lifters push rods and valves.

So... I ended up marking my valve springs with a paint marker and gave her a good rev to 4k and lo and behold.... My valves were floating

(photos attached)

Hope no one else runs into this issue, but on the bright side the LT1 is a non interference engine in stock trim

Good Luck out there and remember to be thorough when troubleshooting.

10-29-2019, 01:44 PM	#1
Azure_King Drives: 2016 Camaro SS Join Date: Oct 2019 Location: Ca Posts: 7	Misfire at 3k rpm, Help! So, new to the forum, nice to meet everyone! I have a 2016 Camaro SS with 57k on the clock; It has a misfire on cylinders 5&8 between 3-4k Rpm. So far I have replaced all fuel injectors, the fuel pumps and the ignition system(plugs, wires, and coils) this has been an issue since i bought the car a year ago and I’ve taken it to two chevy dealers and they can’t seem to figure out whats wrong. Recently I reset the torque on all the rocker arms just incase something was too tight and to make sure i didn't have a weak or collapsed lifter... Any Ideas? Thanks in advance! P.s. the car is stock aside from long tubes, and a tune.

10-30-2019, 09:28 AM	#5
sal11585 Drives: 2017 Camaro SS 2ss Nightfall Gray Join Date: Aug 2018 Location: New york Posts: 149	I am no expert , but maybe its something electrical . Maybe the wiring to the coils or something. Especially since its always done it and looking at what you replaced already, I cant think of anything else it could be. __________________ ACS front spoiler, rear spoiler, side skirts and rock guards (gloss black). Real carbon fiber dash insert, real carbon fiber gear bezel, GM dark tail lights, Gm black badges(Emblems and ss) Powder-coated gloss black factory 5 spoke split wheels Roto fab Biggulp CAI Full paint correction with cquartz finest ceramic coating Whipple 2.9 ARH Long tube headers with High flow cats 1le sway bars F&R BMR Upper and lower trailing arms Hurst short throw shifter

02-06-2020, 09:59 PM	#12
Azure_King Drives: 2016 Camaro SS Join Date: Oct 2019 Location: Ca Posts: 7	Update: Maybe I can save someone a headache later down the line So, the misfire came back a few weeks after the aforementioned parts were replaced So, I took my time and diagnosed a little better.... Misfire only happened at 3k or higher steady state throttle. I already ruled out the ignition system, fuel system, and the possibility of damaged lifters push rods and valves. So... I ended up marking my valve springs with a paint marker and gave her a good rev to 4k and lo and behold.... My valves were floating (photos attached) Hope no one else runs into this issue, but on the bright side the LT1 is a non interference engine in stock trim Good Luck out there and remember to be thorough when troubleshooting. Attached Images

10-29-2019, 01:51 PM	#2
ssmofo Drives: Chevy Camaro Join Date: Jul 2019 Location: Dallas Posts: 420	I would suspect the tune if you have changed all that, does it bring on the CEL?

10-29-2019, 02:50 PM	#3
Wilka_SS Drives: 2016 Nightfall Metallic Grey 2ss Join Date: Oct 2017 Location: New Orleans, LA Posts: 121	Check for a broken valvespring or carbon collected on either of the intake and exhaust valves preventing the valve from seating and sealing.

10-29-2019, 03:01 PM	#4
Azure_King Drives: 2016 Camaro SS Join Date: Oct 2019 Location: Ca Posts: 7	@SSMoFo- this has been an ongoing issue since the car was bone stock; CEL flashes but doesn’t stay on. @Wilka_SS- None of my valve springs appear to be cracked or broken... I’ll have to check throughly for carbon buildup on valves.

10-31-2019, 07:05 AM	#6
Cechk01 Drives: 2016 Camaro 2SS M6 Join Date: Mar 2019 Location: Raleigh Posts: 56	it should still be under powertrain warranty, tell the dealer to fix it

11-02-2019, 08:47 PM	#11
Azure_King Drives: 2016 Camaro SS Join Date: Oct 2019 Location: Ca Posts: 7	Update: As of right now there is no more misfire, we’ll see what happens when I take her back to the dyno... Things I did: checked all wiring from the ECM to each coil(no issues found), checked all ECM fuses and relays(no issues found), Replaced all pushrods and re-gapped spark plugs from .040 to .035. Thanks for the input guys!

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