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Discussion Starter #1
I've noticed that fairly frequently my Volt makes a noise resemblant to backfiring when the engine starts. It seems to happen more at low speeds and less at speeds of 40MPH or higher. Right as the ICE starts, I can usually hear a pop or two coming from the rear of the vehicle that sounds a bit like somebody slapping the muffler with a plastic ruler.

My vehicle went for about a year without much ICE use by the previous owner; it made me put fresh gas in through Fuel Maintenance Mode right after I bought it a few weeks ago. Could that have something to do with it? Or is it something completely different from a backfire?

It seems odd that a nearly brand-new fuel injected engine would backfire but that's definitely what it sounds like.
 

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I would bring to the dealer and describe the problem. The engine control module may need reprogramming. Some 2016's had engine running issues fixed by a module reprogram.
 

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I've noticed a similar thing on my '17. I plan on bringing it up to my dealer when I take the car in for the 7500 mile service. It sounds more like a rattle near the muffler when the ICE starts up - definitely not a backfire.
 

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Discussion Starter #4 (Edited)
I'm scheduled to have a number of recalls fixed tomorrow because neither the previous owner or the dealer where I bought it (certified...) had them performed, so I'll definitely mention it to them. Hopefully it won't require part replacement, but if it does I assume my warranty will cover them.
 

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Do a search on "engine misfire." The 2016 definitely has an engine misfire problem. GM has an engine misfire software update that is supposed to correct the problem. However, I had the update done on my 2016 and it still has the problem. It's not severe enough that I have any heartburn over it, so I'll just let it go. I'm more displeased with the incessant engine oil leak that the dealer has now failed to fix in 3 attempts. Yeah, I know, lemon law and all that. But I'll just give them another crack at it in late December (when I will need to take it in for a tire rotation).
 

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Discussion Starter #6
I'll ask about that when I go in tomorrow. The service tech at my local dealer found three open recalls for my Volt:

43940 TO INSPECT THE SHIFTER

38240 TO INSPECT THE MANUAL SEAT ADJUSTER TRACKS

27660 TO REPROGRAM THE DRIVE POWER MOTOR INVERTER.

I'm excited to get 27660 fixed because apparently it improves the regen paddle and brakes a bit, but I'll ask him if there's a chance it needs to have the Engine Misfire (32340) recall done as well, because like I said, a new car should not be backfiring... :/
 

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I'll ask about that when I go in tomorrow. The service tech at my local dealer found three open recalls for my Volt:

43940 TO INSPECT THE SHIFTER

38240 TO INSPECT THE MANUAL SEAT ADJUSTER TRACKS

27660 TO REPROGRAM THE DRIVE POWER MOTOR INVERTER.

I'm excited to get 27660 fixed because apparently it improves the regen paddle and brakes a bit, but I'll ask him if there's a chance it needs to have the Engine Misfire (32340) recall done as well, because like I said, a new car should not be backfiring... :/
For the misfire, see if you can duplicate the problem with them there, maybe by using Hold mode to get the engine to start? If it's repeatable, having them hear it for themselves will help to determine if it's truly misfiring or a rattle that needs attention, etc.
 

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Discussion Starter #8
That's a good idea. I have a 60-mile-each-way commute and I usually use Hold mode on the interstate but I still never make it back home with any EV miles left, and since I'm going to the dealer by my house tomorrow (leaving work early) I'll actually have it down into extended-range mode already. That'll also mean the engine will be warmed up plenty, as it seems it does it more when the coolant temperature reaches the 210s or higher.
 

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Discussion Starter #10
By chance, Arcanox, did it sound like the video in the following thread:

http://gm-volt.com/forum/showthread.php?252514-Bang-Click-noise-coming-from-rear-passenger-side-2016-Chevy-Volt&highlight=bang

I'm still looking for some free time to bring my Volt in (it behaves just like the video in the thread above) but can't stand to not have it for more than a day.
Good find! I looked around the forum and didn't see any other threads about it, but I guess I didn't look hard enough. Yes, that's almost exactly what mine sounds like (although I've only heard it from the inside with the windows up...Chicago autumn is pretty chilly during the times I commute).

That video shows a spark coming from the exhaust...I have a feeling it has something to do with a tailpipe backfire...maybe the ECU injects fuel a tad too soon as it's starting the ICE (before ignition comes on) and a bit of unburnt vapor reaches the tailpipe?
 
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Hey everyone! We've noticed quite a few of you have been concerned about this 'backfire noise.' We took the opportunity to get in touch with our technical engineering team and want to assure you all that this is considered normal operation.

If anybody has additional questions/concerns, please feel free to send us a private message. We're always here and happy to help.

All the best,

Lauren E.
Chevrolet Customer Care
 

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Hey everyone! We've noticed quite a few of you have been concerned about this 'backfire noise.' We took the opportunity to get in touch with our technical engineering team and want to assure you all that this is considered normal operation.

If anybody has additional questions/concerns, please feel free to send us a private message. We're always here and happy to help.

All the best,

Lauren E.
Chevrolet Customer Care
My 1965 Porsche 365SC cabriolet (bought new by me) would backfire when I let off the gas while going down a hill in second gear. The dealer never told me that that was normal for the car and they had a difficult time getting rid of the backfire as I recall. I find it hard to believe that a new Volt backfiring is considered within the design parameters of the car. Can you imagine a Cadillac backfiring as it was driven down the road? Neither can I. Oh, wait.... this is a Chevrolet. Chevrolets backfire when going down the road and it is considered normal by the engineering team. Hummm.... somehow that doesn't sound right (pun intended).
 

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Er, what? Backfires are considered normal? LOL. Sure, for a car that has a problem, it is normal.

My Volt has never, ever, ever backfired in 5+ years. None of my other cars did either. My tractor does sometimes when the gas mixture is off, a sign to adjust the fuel mixture.

But hey, since it is normal, does that mean my Volt needs to be repaired so it backfires while I drive it? Sheesh
 

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Uh oh... my 2017 Volt sounds abnormal. It doesn't backfire!
 

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Lauren, as others have stated, backfire typically is abnormal behavior in cars with an ICE. Also, majority of Volt owners don't have this issue. Is there more background info you can provide as to why this shouldn't be a concern?
 

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Yesterday I test drove a 2017 Volt LT which was built in August. It too had this backfire problem at least twice during the drive. It also had the mild chuggle issue. The only ICE issue I've ever had with both of my Gen1 Volts (100k miles cumulative) was engine stumbling due to some bad gas. In addition, it wouldn't properly play my common Sandisk 8GB thumb drive which plays flawlessly in my 2015 Volt. While the gen2 has a lot going for it, this and other issues I've read about made me decide to keep my 2015 even though I have a generous GM card incentive to use right now. Not a big sacrifice because I still love the Gen1. Sorry.
 

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Give Lauren a break.
She's just the messenger/apologists in her position. These telephone jockeys are angels. They have to deal with the public all day long.
Maybe she spoke to an intern engineer that just wanted to get off the phone with her....

Hopefully a group of Serious GM Power Train Engineers are looking into this problem.
And a SW update is coming someday....
 

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Discussion Starter #18
I PM'd the GM Customer Service account and asked kindly if they could have an engineer send me a technically detailed description of why the noise occurs, so I guess we'll see what happens. I'd at least like to know why it's normal for my 2016 electric car to backfire.
 

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Discussion Starter #20
Correct, the ICE backfires when it starts up.

I have a 50-mile-each-way commute to/from work every day with (currently) no ability to charge at work, so my ICE runs a considerable amount every day. I run it in Hold mode for about 10 miles on the expressway on the way there, and usually have about 10-15 miles left when I get to work. It runs down part way home, usually before reaching the expressway, so I'm still in stop/go traffic meaning the ICE has plenty of start/stop cycles during my daily commute.

And yeah, it's definitely not normal for a modern ICE to backfire. My previous '06 Highlander Hybrid didn't backfire when its ICE started...my mom's RAV4 doesn't backfire...my dad's MK-Z Hybrid doesn't backfire...why does the Volt? :confused:
 
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