Loud pop from under the car while in reverse [not the brakes]...

[AdamEL]

I did a search for this and couldn't find this exact topic. So feel free to link me if you know of an existing thread.

Tonight, when I was backing out of my garage, I heard a pretty loud "pop" come from the bottom of my Camaro. It was just sort of out of nowhere. I was in reverse, just letting the clutch out [no gas] to ease it down the driveway. I was about 15 seconds or so into my backing out when I heard the pop from underneath. My wife definitely noticed it, too, and that's saying something...

The noise was very similar to the popping sound that your brakes can make when you wash your car and let it sit overnight, and then fire it up the next day or so. When you release the brakes to move the wheels, they'll almost always pop at you. My V6 and my SS both did it, and I know it's common, especially with big wheels. But I don't think that was it because my brakes weren't wet, I had driven the car to work today and there was no rain all day. And additionally, I was already well into rolling the car. So I'm pretty confident that's not the culprit. But the noise was similar to that brake pop.

When we got home, I crawled under the car, and from what I can tell, everything looks good, although I'm not a mechanic. The only mods I have are an Apex Skip-Shift Eliminator and DMH exhaust cutouts. The cutouts look and sound fine, so I doubt that's the problem.

Anybody have any idea what this might be? The car seems to be running as great as ever, so I'm not super worried that it's something crazy. But if anybody thinks I should have it looked at, I will definitely do so.

Thanks for the advice.

[wayner]

Sometimes when you drive over a larger stone at low speed on the very edge of the tire it will fling the stone sideways ,making a loud pop.

Just one scenario to think about

[dcoates18481]

Mine did this once while backing out, i was turning and thats when i heard it.
dealer said it was the differential clitches letting loose.. it had been sottong for 3 weeks and limited slip clutches were"grabby"
i have since added redline gear oil...quieter rear end and no more popping.

[AdamEL]

Originally Posted by dcoates18481

Mine did this once while backing out, i was turning and thats when i heard it.
dealer said it was the differential clitches letting loose.. it had been sottong for 3 weeks and limited slip clutches were"grabby"
i have since added redline gear oil...quieter rear end and no more popping.

This sounds very possible! And I WAS turning the wheel at that time. Did your dealer recommend that gear oil, or you just did that on your own? Can that pop damage the car in any way that you know of?

Thanks for the info!

[Mr_Draco]

Since you have a '10 it could very well be this.

http://www.camaro5.com/forums/showthread.php?t=225109

GM accidentally left out these washers during the first half of the '10 MY. At first it only happens after you've been going in one direction for 10-15 seconds but eventually it gets bad enough to do it immediately after.

[AdamEL]

Originally Posted by Mr_Draco

Since you have a '10 it could very well be this.

http://www.camaro5.com/forums/showthread.php?t=225109

GM accidentally left out these washers during the first half of the '10 MY. At first it only happens after you've been going in one direction for 10-15 seconds but eventually it gets bad enough to do it immediately after.

Thank you for the link! I watched the video and actually read that entire 6 page thread, but that clicking noise doesn't sound anything like what I heard. Mine was way more of a loud "pop" and it was well into my roll and my wheels were turned. I really don't think that's it. However, I am having a tough time understanding weather or not my VIN falls in that category or not. The OP claimed his was in the affected range, but according to the VIN decoder, his should have been the 109,067th Camaro in 2010, not the 9,067th made. Unless I'm somehow misunderstanding that code. My VIN is 2G1FS1EW7A9109564. Do you have any idea if that falls in that date range or not? I'm not hearing that type of click noise, though...

Thank you for the help.

[harrycamaro]

I think I've heard my car make that noise. A little bothersome but I didn't think it was a big deal. Looks like imma have to go pay more attention to it

[dcoates18481]

Originally Posted by AdamEL

This sounds very possible! And I WAS turning the wheel at that time. Did your dealer recommend that gear oil, or you just did that on your own? Can that pop damage the car in any way that you know of?

Thanks for the info!

Dealer added a friction modifier after changing the gear oil.
I went to redline because i like their products and the modifier is already in the oil.
a matter of preference really.

[Mr_Draco]

Originally Posted by AdamEL

Thank you for the link! I watched the video and actually read that entire 6 page thread, but that clicking noise doesn't sound anything like what I heard. Mine was way more of a loud "pop" and it was well into my roll and my wheels were turned. I really don't think that's it. However, I am having a tough time understanding weather or not my VIN falls in that category or not. The OP claimed his was in the affected range, but according to the VIN decoder, his should have been the 109,067th Camaro in 2010, not the 9,067th made. Unless I'm somehow misunderstanding that code. My VIN is 2G1FS1EW7A9109564. Do you have any idea if that falls in that date range or not? I'm not hearing that type of click noise, though...

Thank you for the help.

Yea you're not understanding how the last 6 digits are decoded. When you are trying to figure out what number your car is, just ignore the 1. The 1 just means that it is a production model. The preproduction builds had a 0 in this slot. Once the build count reaches 100,000 it gets more complicated.

Your car is the 9,564th car made. I think GM was making about 400 cars a week at this time so you car was made just a little over a week after his. I don't know what the cut off is but with your car being so close to a car that we confirmed to be effected, it's a very good chance that your car also has this issue.

[AdamEL]

Originally Posted by Mr_Draco

Yea you're not understanding how the last 6 digits are decoded. When you are trying to figure out what number your car is, just ignore the 1. The 1 just means that it is a production model. The preproduction builds had a 0 in this slot. Once the build count reaches 100,000 it gets more complicated.

Your car is the 9,564th car made. I think GM was making about 400 cars a week at this time so you car was made just a little over a week after his. I don't know what the cut off is but with your car being so close to a car that we confirmed to be effected, it's a very good chance that your car also has this issue.

That makes perfect sense. Thank you for the clarification on the VIN number. I want to get it at least looked at for the missing washer. However, mine definitely isn't making that noise. That one guy chimed in on that thread saying that it wasn't all of the models made in that 97,000. So maybe I lucked out on that. But then again, some guys weren't noticing the noise until 30,000 miles and up. Mine only has 6,000 miles on it, so maybe I've got a ways to go. Either way, I'll certainly get it looked at.

Do you have any idea weather or not the absence of that washer can hurt the vehicle in any way?

[AdamEL]

Originally Posted by dcoates18481

Dealer added a friction modifier after changing the gear oil.
I went to redline because i like their products and the modifier is already in the oil.
a matter of preference really.

Oh, okay, gotcha. Thank you for the info.