Any ideas on these two separate noises?

[MrPace]

I have a 2013 2SS L99 with 3500 miles on it...took delivery in early September. Changed the oil around 1500 miles.

After the break in period was over, and I started to get into it more, I have come to notice this noise that is starting to bother me.

It's a barely perceptible metallic-type rattle...and I only hear it when accelerating slowly from a dead stop. It's a rattly, pingy, grindy, almost "crunchy" kind of sound...that's the best way I can describe it, and like I said, it's BARELY perceptible. I'm sure if I had a tech take a test drive of it, they'd say they don't hear anything...has anyone heard of such an engine noise before? If I had to peg a location for the noise, it seems like it's coming from the lower middle back-of-the-engine area, just to the right of the accelerator peddle, but that's just a good guess on my part.

I have the RANGE AFM disable installed, so it's not a noise associated with AFM.

And on a separate issue, I was driving home (it was about a 15 mile drive) about a week ago at night in the rain and there were a lot of leaves on the road during the trip...as I was nearing the end of my trip, the car started to make a loud whining noise, kind of like the classic belt slip/loose belt noise, but not quite like that...the noise started as I was coasting to a stop (no braking yet), and resolved itself in a way like something finally "kicked in"...hard to describe...it lasted about 10-15 seconds...it didn't cause a CEL or any lights for that matter...and hasn't happened again...I'm not even sure if the noise was coming from the engine, as the engine felt fine while this was happening...almost seemed like it was coming from the mid to rear section of the car...but it was rather loud and quite noticeable...any clues?

[ChrisBlair]

has the "rattly, pingy, grindy, almost "crunchy" kind of sound" also appeared with the beginning of colder weather?

This "loud whining noise"...do you manually tapshift or similar? It was really a high pitched squeal like a loose belt? Because usually...that's a loose belt, lol

[freddyD]

I have a 2014 ls and it makes a strange noise,but when I,m stopped or comming to a stop sounds like ABS motor-weird sound-like a creaky door in a haunted house!Wots up wit dat?only 600 miles.

[lawdog]

I would guess the abs for the second noise !
Not enough info to help with the first

[lawdog]

Ist noise may be some loose material in the cats, just a thought.

[blackswan]

Originally Posted by lawdog

Ist noise may be some loose material in the cats, just a thought.

Could very well be the right guess. I had a similar noise and the fix was to replace the O2 sensors and converter on one side.

The noise is coming back :(

[MrPace]

Originally Posted by ChrisBlair

has the "rattly, pingy, grindy, almost "crunchy" kind of sound" also appeared with the beginning of colder weather?

This "loud whining noise"...do you manually tapshift or similar? It was really a high pitched squeal like a loose belt? Because usually...that's a loose belt, lol

No, the noise first started before the colder weather hit.

[MrPace]

Originally Posted by lawdog

I would guess the abs for the second noise !
Not enough info to help with the first

Regarding the second noise, I wasn't using the brakes when that noise first began, and I wasn't slipping/sliding at all so I don't see why the ABS would have been active.

Is it common for a belt to slip at the end of a ride? I thought they normally slip when a car is first started. Also, I was wondering if somehow the rain or slick leaves possibly caused something temporary to happen...I know, unlikely, but wondering if possible. Like I said, I haven't heard the noise again, and it's been a few weeks.

[Chevrolet Customer Svc]

Originally Posted by MrPace

I have a 2013 2SS L99 with 3500 miles on it...took delivery in early September. Changed the oil around 1500 miles.

After the break in period was over, and I started to get into it more, I have come to notice this noise that is starting to bother me.

It's a barely perceptible metallic-type rattle...and I only hear it when accelerating slowly from a dead stop. It's a rattly, pingy, grindy, almost "crunchy" kind of sound...that's the best way I can describe it, and like I said, it's BARELY perceptible. I'm sure if I had a tech take a test drive of it, they'd say they don't hear anything...has anyone heard of such an engine noise before? If I had to peg a location for the noise, it seems like it's coming from the lower middle back-of-the-engine area, just to the right of the accelerator peddle, but that's just a good guess on my part.

I have the RANGE AFM disable installed, so it's not a noise associated with AFM.

And on a separate issue, I was driving home (it was about a 15 mile drive) about a week ago at night in the rain and there were a lot of leaves on the road during the trip...as I was nearing the end of my trip, the car started to make a loud whining noise, kind of like the classic belt slip/loose belt noise, but not quite like that...the noise started as I was coasting to a stop (no braking yet), and resolved itself in a way like something finally "kicked in"...hard to describe...it lasted about 10-15 seconds...it didn't cause a CEL or any lights for that matter...and hasn't happened again...I'm not even sure if the noise was coming from the engine, as the engine felt fine while this was happening...almost seemed like it was coming from the mid to rear section of the car...but it was rather loud and quite noticeable...any clues?

MrPace,

Sorry to hear about the noises you're hearing. I understand you're seeking opinions and wanted you to know that we're here if your concerns prompt an official diagnosis. Feel free to message us if needed and we'll do what we can do to help resolve these occurrences.

William R.
Chevrolet Customer Care

[KJS]

...I hear a rattly, pingy, grindy, screechy noise from the passenger seat while I'm driving.....

Sorry hun.