Loud bang: a mystery

toyota
corolla

#1

The car is my Corolla from here: Evap control errors
Today, for the first time in my life, it got stuck in the snow. Stuck for good, permanently. In the middle of D/R switching to get out and a lot of burned rubber smell, the car produced a pretty loud bang – it even rocked a little, I think.
Been running fine since, the tires are fine. I am thinking it was just a rock from under one of the wheels banging into the bottom cover, but since I’ve made the appointment for that evap stuff and the starter nose, I also mentioned this to the mechanic.

For the purposes of a general brainstorming session, what could this bang be?


#2

With no other facts besides loud bang I not even guessing.


#3

The transmission may have been destroyed.

One of the worst things you can do to a transmission is shift it from D/R and back to rock a vehicle to get it unstuck.

Tester


#4

I absolutely agree, but on the OP’s word that it’s running fine now I’m inclined to disagree that it’s been destroyed. I suspect he lucked out. But, than, I can be too much of an optimist at times.

The source of the bang? I have no guess. Perhaps he overstressed a mount. Or hit pavement with the engine spinning at 3,000 rpm and sent a shock wave through the drivetrain. Whatever it was, if something broke but hasn’t shown up yet, I’m betting it will at some point. I hope the OP posts back then.


#5

Besides the ideas above, it might have been an engine backfire, either out the tailpipe or into the intake manifold. Especially if engine stalled a few times while maneuvering out of the snow. If three’s no further symptoms, keep a weather eye out for anything abnormal cropping up, otherwise drive on.


#6

I don’t think I was “rocking” the vehicle that way. I did switch between drive and reverse many times, but there would be probably 30 seconds or even a few minutes between the switches. Also, the bang did not occur during switching. Your guess, however, is one of my worst fears at this point, which necessarily means a new car in this case. I was driving the car today, and it seems perfectly fine. Anything specific to ask the mechanic next Friday?


#7

[quote=“GeorgeSanJose, post:5, topic:98213, full:true”]
Besides the ideas above, it might have been an engine backfire, either out the tailpipe or into the intake manifold. Especially if engine stalled a few times while maneuvering out of the snow. If three’s no further symptoms, keep a weather eye out for anything abnormal cropping up, otherwise drive on.[/quote]
Nope, no stalling before or after. No symptoms so far, but will be on the lookout, thanks.


#8

Who knows? But here’s my story. When I was 16 I took our 61 Merc ten miles on the highway to the next town at night. I heard a big bang in the rear like a rock but everything seemed to work fine. A couple days later I took it out again and when turning the signal lights on, all four lights would flash. Had two guys look at it but couldn’t figure it out. Finally I crawled under and started to piece two and two together and look at it myself. I found a big hole in the resonator behind the muffler on that side and the wires above it all melted together. Some wire and a tin can and electrical tape restored the functions. So you never know until later sometimes.


#9

Sure. I’ll be driving it next week before the mechanic looks at it on Friday, so we’ll just wait and see.


#10

Sounds like the perfect reason to pick out a new car.

If you are driving this car it must now be functional. The noise may have been from ice build-up in the wheel well dropping onto the tire and shot rearward or from the vehicle sliding into the curb, the best witness to the event is yourself.

Ask your mechanic if gun fire is common in your area, that is what I hear where I live.


#11

It’s Boulder, CO, for god’s sake. Hipsters slapping each other with flowers over a badly rolled joint.


#12

Here’s a thought. One of the drive axle brakes could have been frozen in the engaged position preventing you from moving, and the noise might have been the brake freeing itself, possibly when the spinning tire hit pavement. You might not have even been aware that one wheel wasn’t spinning, as the differential will allow the other wheel to spin and the engine to rev as if both wheels were free.


#13

I don’t think you qualify as a Hipster, based on the fact you’ve got an older Corolla, versus a new Prius :smirk_cat:

I know a guy in his late 40s, he’s still attempting to convince himself and others he’s a hipster. He drives a Prius and dresses identical to those guys 20 years younger than him. And of course, he’s got the same beard all of them have

The whole thing is quite amusing

No offense intended to any hipsters reading this

:stuck_out_tongue_winking_eye:


#14

[quote=“the_same_mountainbik, post:12, topic:98213, full:true”]
Here’s a thought. One of the drive axle brakes could have been frozen in the engaged position preventing you from moving, and the noise might have been the brake freeing itself, possibly when the spinning tire hit pavement. You might not have even been aware that one wheel wasn’t spinning, as the differential will allow the other wheel to spin and the engine to rev as if both wheels were free.[/quote]
You are the second person to suggest this!


#15

[quote=“db4690, post:13, topic:98213, full:true”]
I don’t think you qualify as a Hipster, based on the fact you’ve got an older Corolla, versus a new Prius :smirk_cat:

I know a guy in his late 40s, he’s still attempting to convince himself and others he’s a hipster. He drives a Prius and dresses identical to those guys 20 years younger than him. And of course, he’s got the same beard all of them have[/quote]
Wait, what? I never claimed to be a hipster, though I’m in my 30s. I genuinely want to try Tesla Model 3, that much is true. Is that a hipster thing?
Wouldn’t you guys like to hear EV questions here for a change? :slight_smile:


#16

Well, that’s the thing with the internet

You couldn’t tell that my post was meant to be humorous

On the other hand, YOU were the one that initially made the disparaging remarks about them . . . “slapping each other with flowers over a badly rolled joint.” :blush:

So I was pretty sure you were NOT one of them, and made my comments

As a matter of fact, we do occasionally talk about EVs


#17

Yeah, no, we’re on the same page here. :slight_smile: I am very much a Chicago person who is in Boulder due to a tenured position at a major research institution. The topic of hipsters trying too hard is a sore one for me and my friends. Everyone makes fun of them, yet we are all slowly starting to do the things they do (e.g. buy a Subaru and go to the mountains to annoy the wildlife), and that’s freaking unsettling!