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Do you experience the "clank" (coming from the rear) sporadically when using ICE?

  • Yes

    Votes: 9 60.0%
  • No

    Votes: 6 40.0%

Clank noise when on ICE and making right turn?

8K views 28 replies 15 participants last post by  Saint 
#1 ·
I've got 4000 miles so far, only 130 of those ICE, so I don't have a large sample of ICE miles. However, I have noticed when I am stopped and then proceed to turn right, there is (sometimes) a kind of clank noise that comes from the rear. Any idea what that would be? It makes one single, clean, clank and only happens in the scenario above. I don't think it does it every time, but it definitely is something. Any ideas? There is absolutely nothing in the rear hatch and it never does this on EV mode. Yes, I know I need to take it to the shop, but what could it be?
 
#2 ·
At first I thought it had to be. Suspension thing and the ice only was coincidence, but maybe it has something to do with the exhaust since that should be vibrating with the ice on.
 
#6 ·
UPDATE:

So after driving some more ICE miles, only a total of 300ish so far, I can say the clank occurs only when the engine first kicks in, is not related to turns, and does not occur each time the ICE starts. It is a sound coming from the rear, sounds like bottom rear of the car. When I say it happens when the engine kicks in, I don't mean only when ICE starts after the battery is depleted, I mean it happens when the ICE activates when on ICE mode...when the display indicates the ICE is supplying power. That means this happens multiple times during an ICE trip.

I'd like to know if anyone else experiences this.
 
#9 · (Edited)
Yes, I've experienced the same "clank" noise that appears to come from the rear underside of the car. I heard it for the first time on a 1000-mile road trip a couple weeks back when I was running the ICE quite a bit (I have about 4000 miles on the car now). For me, the sound coincides with the moment the ICE kicks on and is most apparent when I first pull away from a stop. I can't hear the noise if the ICE kicks in while driving at higher speeds but it could be masked by road noise. Also, I don't think the noise occurs every time the ICE engages. One thought I had is that the sound might be coming from an emission control valve in the fuel tank venting system (e.g. a valve that switches state to divert tank vapors to the engine intake when it's running.) If the valve is mounted on or near the fuel tank (rear of the car) then the valve switching sound might be transmitted through the structure. Will continue to monitor if anything changes. Most of my miles are EV only so I won't be listening for the noise until the next extended range trip.
 
#12 ·
I have the same problem. It occurs only when running the ICE and is noticeable when I press on the pedal from a stop. While driving, when I take my foot off the pedal and again press, the noise is evident. Not noticeable on freeway driving but evident on surface streets. The noise comes from the rear underside of the car and somewhat resembles the sound of a linkage movement. It’s one of those dealer visits you don’t look forward to; the problem is intermittent and hard to describe.

2016 Summit White (Oct. 2015 Build)
 
#13 · (Edited)
Yeah, I believe it only occurs when I'm stopped or at lower speeds and then kick on the ICE. I can't say I've heard it at highway speeds.

Just to add clarity, lets say I drive on ICE 10 miles in the city. The ICE will engage at various times during the trip as the car goes from battery only mode and then engaging the ICE. I probably would hear this noise 5+ times at least during that trip. That's only a fraction of ICE kick ons, so to speak, but very noticeable and not normal operation.
 
#15 ·
I've definitely noticed this exact problem with my 2016 volt. When I took it to the Chevy dealer for an inspection, they were unable (or unwilling) to replicate the sound. I hope you get to the bottom of this. Please report back with any updates from the dealer. Thank you!
 
#17 ·
miamialley, does it perhaps sound like the video in the OP in this thread:

http://gm-volt.com/forum/showthread...ming-from-rear-passenger-side-2016-Chevy-Volt

If so, you're not alone. So far, officials from Chevy monitoring this forum have told us this is normal and to standby while they get a better explanation from their techs and engineers. If you're experiencing the same thing, I'd suggest PM'ing them as well. At this rate, I'll probably bring it in for servicing too.

Another thread on the matter (more of the same):

http://gm-volt.com/forum/showthread.php?261057-16-Volt-backfiring
 
#19 ·
[cross posted from this thread for future searchers]

(some background, I tried changing from gas mixed with 10% ethanol to pure gas, the kind you find at marinas, to see if it changed the behavior of the after fires/bang sounds)

So I filled up my tank from 1.6 gas+ethanol (I forget the %, but I think 10% is safe to assume) to 8.9 of pure gas. Given similar ambients so far (50F morning commute on ICE, 60F-75F evenings on ICE) I think I'm getting more afterfires now. I used to only get a single bang, but now I occasionally get 2 in a row from a single acceleration. I do not think I let off accelerator then re-apply accelerator, just a single, smooth acceleration.

It's now annoying me. I prefer the single afterfire. Seems to me the fuel mixture is getting more rich? I thought modern ICE engines have various sensors that prevent oddities like knocking and misfires.
 
#20 ·
Just picked up my 2017 Volt a few weeks ago. I get the same sound on my car when in ICE mode. Almost like a something has shifted in the trunk but there is nothing in there. I have appointment with the dealer to show them the issue and to see what can be done. Will report back to what I find out. This only happens in ICE and not in EV mode. Most of the time it's from a standstill pulling away when the ICE kicks in.

Also will see if there is any software updates they need to do as I am sure thy didn't do any when I picked up the car.
 
#21 ·
Ok update from the dealer.

Said the noise is actually coming from the front not the back. They had someone sit in the trunk area to see if the could locate it. But its in the front according to them.

They told me it's perfectly normal for the car. It was the Stator kicking in and they tend to make a bit of noise.

As for the software updates the dealer needs to call in the tech to do them. Have another appointment to go in in 5 days. Said they will update the radio but any other updates there needs to be a reported incident.

Is there a must have for a 2017 built in January that I need to be on the lookout for?
 
#22 ·
I'll have to make sure I engage ICE in HOLD and CS mode with a passenger/helper in the rear seat. Just in case my ears are fooling me.

Quick google tells me a stator is part of an inductive motor. So this would be either MGA or MGB in our Volts, right? Does your dealer mean it's the electric motors causing the bang sound during initial, moderate acceleration? Cause I've gunned with some battery level left and it doesn't make any bang sounds. Only sounds I hear are tires squealing and a high pitched "whir". I don't think the dealer techs are right about it being the "stator".
 
#24 ·
My 2017 Volt does the same thing! Last night was the first time I ran the ICE and it makes that thunk/tick noise (honestly sounds like the ICE's starter motor engaging). I was driving at relatively low speeds around town in HOLD. I don't think that this is normal but I also don't think that its a big deal in the sense that anything is significantly wrong.

Maybe something to do with the starter or motor mounts?

Looks like I've got a trip to the dealership ahead of me..
 
#25 ·
(honestly sounds like the ICE's starter motor engaging).
Except the ice doesn't really have a starter motor. It leeches momentum off of one of the electric motors to get moving, and that doesn't sound like a traditional starter motor at all.
 
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