Loud Hesitation / Pop sound from Exhaust

bigcamaroguy · 09-06-2021, 10:35 AM

Let my girlfriend drive my sacred 2016 2SS and she apparently put 97 octane into the car (literally have never seen that at a gas station so was honestly
Impressed at how she even found that). I always go 93, told her to go 93 if she filled up. Anyway, after I broke up with her (jk) about 20 mins later while driving - the car suddenly dropped octaves and began “popping / farting” around 1000rpm. Immediately pulled over and checked everything out. It’s not a tranny issue. Drained all the bad gas and put premium back in - problem is continuing. Any ideas as to what this is? Fuel pump / injector / exhaust leak? There are no check engine lights or anything. Have taken to two dealerships and they have basically said “it sounds like something is wrong but we don’t know what”.

Posting a video link in a sec. Any help is massively appreciated.

bigcamaroguy · 09-06-2021, 10:44 AM

https://youtu.be/fdS_sDb3rKs

It happens very early in the vid. You can hear the rattle (car basically gets a deeper bass sound) then pop. The Pop is at the 5 second mark.

https://youtu.be/L6eoxH_ERDM

JKSully · 09-06-2021, 10:52 AM

I've never heard of 97 octane myself - 87 is common, though, perhaps that's what she used by mistake? For the sound, it's hard to hear much in that video - is it at the 3 - 4 second mark? Honestly thought that was a suspension noise, but then again my ears are fried from too many concerts in my youth...

avalonandl · 09-06-2021, 10:56 AM

Sounds like you got some BAD gas...

bigcamaroguy · 09-06-2021, 10:59 AM

Quote:

Originally Posted by JKSully

I've never heard of 97 octane myself - 87 is common, though, perhaps that's what she used by mistake? For the sound, it's hard to hear much in that video - is it at the 3 - 4 second mark? Honestly thought that was a suspension noise, but then again my ears are fried from too many concerts in my youth...

I hadn’t either. We retraced her steps and went back to the gas station she went to and there it was…. 97. Was the world’s sketchiest gas station lmao.

Yes the shake / rattle is at the 3-4 second mark. The car basically drops octaves and gets a “bass” sound like it’s about to drop in an EDM song and then the pop follows right after. I’ll try to get a better vid - it’s ridiculously noticeable in person and vids aren’t doing it any justice.

bigcamaroguy · 09-06-2021, 11:01 AM

Quote:

Originally Posted by avalonandl

Sounds like you got some BAD gas...

Sadly tums can’t fix this one :’(

SSUNDVL · 09-06-2021, 11:21 AM

I wouldn't worry about it, 2 dealers say they can't find anything, probably not bad gas and if it drives fine with no lights seems like no issue. These cars make noise and after letting someone drive it is always going to seem like something is off if you haven't noticed something before.

SomeGeoffGuy · 09-06-2021, 12:00 PM

Was it leaded race gas? If it was, your O2's are trashed and maybe your cats. Good news is that it shouldn't cause anything permanent once you replace that stuff (assuming it was leaded).

-Geoff

bigcamaroguy · 09-06-2021, 06:42 PM

Quote:

Originally Posted by SomeGeoffGuy

Was it leaded race gas? If it was, your O2's are trashed and maybe your cats. Good news is that it shouldn't cause anything permanent once you replace that stuff (assuming it was leaded).

-Geoff

Yes after driving back to the station + some digging I found out that it was. Thanks for the response.

Nilly Welson · 09-06-2021, 07:58 PM

Quote:

Originally Posted by bigcamaroguy

Let my girlfriend drive my sacred 2016 2SS and she apparently put 97 octane into the car (literally have never seen that at a gas station so was honestly
Impressed at how she even found that). I always go 93, told her to go 93 if she filled up. Anyway, after I broke up with her (jk) about 20 mins later while driving - the car suddenly dropped octaves and began “popping / farting” around 1000rpm. Immediately pulled over and checked everything out. It’s not a tranny issue. Drained all the bad gas and put premium back in - problem is continuing. Any ideas as to what this is? Fuel pump / injector / exhaust leak? There are no check engine lights or anything. Have taken to two dealerships and they have basically said “it sounds like something is wrong but we don’t know what”.

Posting a video link in a sec. Any help is massively appreciated.

What station is selling 97 Octane? I thought 93 was the max now.

arpad_m · 09-06-2021, 10:57 PM

Quote:

Originally Posted by Nilly Welson

What station is selling 97 Octane? I thought 93 was the max now.

I'd venture that it was 87 and the (sketchy as per the OP) gas station mislabeled it as 97. For what it's worth, I have never seen 97 octane sold at the pump in any state I've been in.

SomeGeoffGuy · 09-07-2021, 12:39 AM

Quote:

Originally Posted by bigcamaroguy

Yes after driving back to the station + some digging I found out that it was. Thanks for the response.

That's crazy - did you ask her how she got the gas in? Usually the leaded fuel pumps have an oversize nozzle that wont even fit in the fill hole on a car built since 1972.

At least it is not the end of the world. I would do the O2's first, then if that doesn't work - time for some headers with an off-road pipe!

-Geoff

2SS Capt · 09-07-2021, 12:53 AM

Quote:

Originally Posted by SomeGeoffGuy

Was it leaded race gas? If it was, your O2's are trashed and maybe your cats. Good news is that it shouldn't cause anything permanent once you replace that stuff (assuming it was leaded).

-Geoff

Quote:

Originally Posted by bigcamaroguy

Yes after driving back to the station + some digging I found out that it was. Thanks for the response.

That's going to cost you some $$$ Cat's aren't cheap...

Lesson for you, DO NOT let girlfriends or wives' drive your hot rod!!! They usually do NOT know what they are doing!

SomeGeoffGuy · 09-07-2021, 03:17 PM

You know, the more I think about it, if you can prove that the gas station had the incorrect fill nozzle on the pump, you may be able to report the damage to your insurance company. Or if you are felling litigious, you could try to get the station to pay! There is a reason the nozzle for leaded fuel is supposed to be bigger - to prevent your girlfriend from doing what she did.

-Geoff

09-06-2021, 10:35 AM	#1
bigcamaroguy Drives: 2016 Camaro 2SS Join Date: Sep 2021 Location: Ohio Posts: 5	Loud Hesitation / Pop sound from Exhaust Let my girlfriend drive my sacred 2016 2SS and she apparently put 97 octane into the car (literally have never seen that at a gas station so was honestly Impressed at how she even found that). I always go 93, told her to go 93 if she filled up. Anyway, after I broke up with her (jk) about 20 mins later while driving - the car suddenly dropped octaves and began “popping / farting” around 1000rpm. Immediately pulled over and checked everything out. It’s not a tranny issue. Drained all the bad gas and put premium back in - problem is continuing. Any ideas as to what this is? Fuel pump / injector / exhaust leak? There are no check engine lights or anything. Have taken to two dealerships and they have basically said “it sounds like something is wrong but we don’t know what”. Posting a video link in a sec. Any help is massively appreciated.

09-06-2021, 10:52 AM	#3
JKSully Drives: 22 Camaro 2SS, 20 Subaru Crosstrek Join Date: Aug 2021 Location: DFW TX Posts: 571	I've never heard of 97 octane myself - 87 is common, though, perhaps that's what she used by mistake? For the sound, it's hard to hear much in that video - is it at the 3 - 4 second mark? Honestly thought that was a suspension noise, but then again my ears are fried from too many concerts in my youth... __________________ Earth is an oblate spheroid 2022 \| 2SS \| M6 \| NPP \| Summit White \| Carbon Flash Wheels \| Black Lugs \| Red Calipers \| Adrenaline Red \| Red Knee Pads \| Nav \| - 1100 - 8/16/21 - 3000 - 9/21/21 - TPW 10/18/21 - 3400 - 10/1/21 - 3800 - 10/20/21 - built 10/19/21 - 5000 - 11/12/21 - 6000 - 11/13/21

09-06-2021, 10:56 AM	#4
avalonandl Drives: 2019 ZL-1 Join Date: Feb 2009 Location: Troy, MI & Naples, FL Posts: 2,019	Sounds like you got some BAD gas... __________________ 2019 ZL-1 Acquired 4/23/21 at 6300 miles. Riverside Blue, A10, PDR. Traded in 2017 2SS with 6M and 32k miles. Continental Extreme Contact Sports. Now has 10,000 miles... 2012 Yukon XL Denali w/ 6.2 AWD

09-06-2021, 12:00 PM	#8
SomeGeoffGuy Drives: 2023 2SS Convertible Join Date: May 2009 Location: Metro Detroit Posts: 1,063	Was it leaded race gas? If it was, your O2's are trashed and maybe your cats. Good news is that it shouldn't cause anything permanent once you replace that stuff (assuming it was leaded). -Geoff __________________ '12 2SS RS Convertible - Traded in. '16 2SS Convertible - White on white, mag-ride, NPP, nav. Sold! '23 2SS Convertible -Same as above except orange.

09-07-2021, 03:17 PM	#14
SomeGeoffGuy Drives: 2023 2SS Convertible Join Date: May 2009 Location: Metro Detroit Posts: 1,063	You know, the more I think about it, if you can prove that the gas station had the incorrect fill nozzle on the pump, you may be able to report the damage to your insurance company. Or if you are felling litigious, you could try to get the station to pay! There is a reason the nozzle for leaded fuel is supposed to be bigger - to prevent your girlfriend from doing what she did. -Geoff __________________ '12 2SS RS Convertible - Traded in. '16 2SS Convertible - White on white, mag-ride, NPP, nav. Sold! '23 2SS Convertible -Same as above except orange.

09-06-2021, 11:21 AM	#7
SSUNDVL Drives: 2016 Camaro SS Join Date: Jul 2020 Location: Dallas, TX Posts: 149	I wouldn't worry about it, 2 dealers say they can't find anything, probably not bad gas and if it drives fine with no lights seems like no issue. These cars make noise and after letting someone drive it is always going to seem like something is off if you haven't noticed something before.

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