Weird sound help

Hoopster3 · 07-26-2018, 07:47 PM

I took the Camaro for its 1st road trip yesterday and came back today. I noticed that from 62-69 MPH when I'm not on the gas (like when the cruise is set) there is a very loud noise coming from the car. It almost sounds like a semi is passing me. If I step on the gas the sound goes away or if I speed up it goes away.

I believe it to be an exhaust leak. My other thought was a tire, but that would seem odd because it's only from 62-69 MPH. What else could it be?

MarkC · 07-26-2018, 09:58 PM

Any chance you have an auto tranny and NPP exhaust? If yes, any chance you pulled the fuse for the front valves? On C7 Vettes the car sounds like crap if the front valves are open in V4 mode.

Hoopster3 · 07-26-2018, 10:47 PM

Yes it's an automatic. I bought the car used. I haven't pulled any fuses. I figured I didn't have NPP because there is no difference in exhaust note when I change driving modes.

SnakeEyeSS · 07-26-2018, 10:58 PM

Quote:

Originally Posted by Hoopster3

Yes it's an automatic. I bought the car used. I haven't pulled any fuses. I figured I didn't have NPP because there is no difference in exhaust note when I change driving modes.

General rule, Four pipes is NPP, two is not. Unless it has a different exhaust....

Cgocifer · 07-26-2018, 11:44 PM

Quote:

Originally Posted by Hoopster3

Yes it's an automatic. I bought the car used. I haven't pulled any fuses. I figured I didn't have NPP because there is no difference in exhaust note when I change driving modes.

You can also manually change the settings of the steering, suspension, exhaust, etc. So, if you set the exhaust to race mode in the settings, even in tour, your exhaust us in race mode. But, yes, if stock exhaust, 4 pipes = NPP.

Doubt that is your noise though. Could be the differential too. Keep us posted if you figure out the noise.

Can you pinpoint where the noise is? Is it a whine, a rumble, a squeal?

Hoopster3 · 07-27-2018, 12:02 AM

I only have 2 pipes, so must not be NPP. I also don't have a race setting. My settings make no difference in exhaust sound.

The sound is hard to describe. Like I first said it sounds like a semi is passing me heading in the same direction I am. I would say there is a little bit of rumble as there are some vibrations felt in the vehicle during this event as well.

It's a 2017 1SS which I bought Certified Pre-owned, so it should be covered...whatever it is. I'll keep you updated after I get it into the dealer.

Cgocifer · 07-27-2018, 12:13 AM

Quote:

Originally Posted by Hoopster3

I only have 2 pipes, so must not be NPP. I also don't have a race setting. My settings make no difference in exhaust sound.

The sound is hard to describe. Like I first said it sounds like a semi is passing me heading in the same direction I am. I would say there is a little bit of rumble as there are some vibrations felt in the vehicle during this event as well.

It's a 2017 1SS which I bought Certified Pre-owned, so it should be covered...whatever it is. I'll keep you updated after I get it into the dealer.

Good luck, hopefully the dealer figures it out and makes it right. Leaning towards a differential issue or u joint somewhere which could be why it wont do it under acceleration due to loading.

ctrlz · 07-27-2018, 09:37 AM

Quote:

Originally Posted by Cgocifer

Leaning towards a differential issue or u joint somewhere which could be why it wont do it under acceleration due to loading.

This has me thinking it is the 4 cylinder AFM mode changing the engine sound.
When you hear the noise in cruise mode, does it go away if you accelerate?

Turkish01 · 07-27-2018, 10:15 AM

Quote:

Originally Posted by ctrlz

This has me thinking it is the 4 cylinder AFM mode changing the engine sound.
When you hear the noise in cruise mode, does it go away if you accelerate?

Agreed, took a little while to get used to that sound

Kise · 07-27-2018, 10:46 AM

im having this same issue but it happens when it shifts to 4th and at 45-50 mph and 70-75. sounds like rumble strips sometimes sometimes light vibrations and shaking. Im assuming it is the torque converter gone bad and you have the A8 Shudder.

taking mine in Monday.

stangs024 · 07-27-2018, 01:34 PM

You can narrow down the cause. Put your shifter in manual mode, progress through gears. Downshift once, or let your car downshift on its own. Until you go back in automatic mode AFM won't activate and you can replicate your driving conditions where you heard the noise/vibration before. If you still hear it, your problem isn't AFM related. If you don't, it's AFM related.

Before I got my AFM disabler I remember a nasty noise/vibration similar to what you're describing. It always seemed to happen RIGHT BEFORE the car would switch back to v8 from v4. Post-AFM disabler I haven't heard the noise.

HackSaw · 07-27-2018, 02:03 PM

Any chance that what Op is hearing is from the sound tube under the dash.

MackSteelPrivateEye · 07-27-2018, 03:52 PM

Quote:

Originally Posted by Hoopster3

I only have 2 pipes, so must not be NPP. I also don't have a race setting. My settings make no difference in exhaust sound.

The sound is hard to describe. Like I first said it sounds like a semi is passing me heading in the same direction I am. I would say there is a little bit of rumble as there are some vibrations felt in the vehicle during this event as well.

It's a 2017 1SS which I bought Certified Pre-owned, so it should be covered...whatever it is. I'll keep you updated after I get it into the dealer.

Sounds like it might be Automatic Trans shudder. Its a known issue with the 8 spd trans.

Hoopster3 · 07-27-2018, 04:54 PM

Quote:

Originally Posted by MackSteelPrivateEye

Sounds like it might be Automatic Trans shudder. Its a known issue with the 8 spd trans.

What's the fix?

07-26-2018, 07:47 PM	#1
Hoopster3 Drives: NFM 1SS Join Date: Jul 2018 Location: Iowa Posts: 25	Weird sound help I took the Camaro for its 1st road trip yesterday and came back today. I noticed that from 62-69 MPH when I'm not on the gas (like when the cruise is set) there is a very loud noise coming from the car. It almost sounds like a semi is passing me. If I step on the gas the sound goes away or if I speed up it goes away. I believe it to be an exhaust leak. My other thought was a tire, but that would seem odd because it's only from 62-69 MPH. What else could it be?

07-26-2018, 09:58 PM	#2
MarkC Drives: 2018 HBM 2SS/1LE Join Date: Jun 2018 Location: 29860 Posts: 85	Any chance you have an auto tranny and NPP exhaust? If yes, any chance you pulled the fuse for the front valves? On C7 Vettes the car sounds like crap if the front valves are open in V4 mode. __________________ 2017 Admiral Blue Corvette** Grand Sport Convertible**

07-26-2018, 10:47 PM	#3
Hoopster3 Drives: NFM 1SS Join Date: Jul 2018 Location: Iowa Posts: 25	Yes it's an automatic. I bought the car used. I haven't pulled any fuses. I figured I didn't have NPP because there is no difference in exhaust note when I change driving modes.

07-27-2018, 12:02 AM	#6
Hoopster3 Drives: NFM 1SS Join Date: Jul 2018 Location: Iowa Posts: 25	I only have 2 pipes, so must not be NPP. I also don't have a race setting. My settings make no difference in exhaust sound. The sound is hard to describe. Like I first said it sounds like a semi is passing me heading in the same direction I am. I would say there is a little bit of rumble as there are some vibrations felt in the vehicle during this event as well. It's a 2017 1SS which I bought Certified Pre-owned, so it should be covered...whatever it is. I'll keep you updated after I get it into the dealer.

07-27-2018, 10:46 AM	#10
Kise Drives: 16' 2SS, 06' Silverado SS Join Date: Jul 2017 Location: Columbus, OH Posts: 345	im having this same issue but it happens when it shifts to 4th and at 45-50 mph and 70-75. sounds like rumble strips sometimes sometimes light vibrations and shaking. Im assuming it is the torque converter gone bad and you have the A8 Shudder. taking mine in Monday.

07-27-2018, 01:34 PM	#11
stangs024 Drives: 2018 camaro ss Join Date: Jun 2018 Location: Dallas Posts: 36	You can narrow down the cause. Put your shifter in manual mode, progress through gears. Downshift once, or let your car downshift on its own. Until you go back in automatic mode AFM won't activate and you can replicate your driving conditions where you heard the noise/vibration before. If you still hear it, your problem isn't AFM related. If you don't, it's AFM related. Before I got my AFM disabler I remember a nasty noise/vibration similar to what you're describing. It always seemed to happen RIGHT BEFORE the car would switch back to v8 from v4. Post-AFM disabler I haven't heard the noise.

07-27-2018, 02:03 PM	#12
HackSaw Drives: 2017 Camaro SS Join Date: May 2018 Location: Portland Oregon Posts: 151	Any chance that what Op is hearing is from the sound tube under the dash.

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