[WhiteMale]

Mine seems to disappear, the noise that I hear that is rattly, within about 30 seconds when it idles down from cold start. I haven't heard it any other time.

[h1nch]

Originally Posted by ZL1 For The Sun

I purchased my new ZL1 a little over a week ago, finally after a 215 mile freeway only trip home it started making the same tick noise others have described in the car as I came into a 25 MPH zone close to home. After carefully pulling into the garage I listened under the car to the same noise others have posted on YouTube. My build date is 5-1-2023. The noise begins after driving to normal temperature and goes away above 1750 rpm. Took it to the closest dealer who heard it and is researching the problem which he thought may be fuel pump related. I’m not driving it until I take it back. Hopefully these posts will help my dealer fix the problem. Thank you all for the help!

Yeah this sounds like the same issue.

In my case, the noise is very much noticeable, but I feel like it's not quite as loud in my car as it is in the example videos posted here, but it's still quite annoying.

For me, the noise also goes away above a certain RPM, though I'm not sure if it is actually going away, or if the engine note is just drowning it out. Generally while driving I don't hear it at all. And at times, it even goes away at idle. I tried wiggling the fuel line like someone else here did, and I feel like it did make the noise quieter, at least temporarily.

I am taking my car to the dealership here in about an hour. I am hoping they can overnight the part. If it's still on backorder I will likely pick the car back up and keep it until it's available. The dealership didn't seem to indicate it was a serious issue requiring the car to be not driven, and I haven't seen any error codes or issues so I've just been driving it normally, if not a little easy (not WOT, no redline)

[ZL1 For The Sun]

Thank you. If you would, let us know how it turned out at the dealer. Hopefully it resolves the problem and we can all use the info to get ours fixed.

[h1nch]

Update: Dealer called today and said that they do believe it to be the fuel line as per the TSB, but part shipping was delayed and is now expected to arrive between 8/17 and 8/23, so I went back to get my car. My saga continues.

When I retrieved the car at the dealership, the sound was present. After 20+ mins of driving when I pulled into a gas station, the sound was gone (before and after fuel up)

Car still drives awesome so I'm happy that I get to drive it instead of the Sentra they gave me as a loaner.

[WhiteMale]

SO this isn't a line rattling, it's more complex than that...right?

[DangerZL1]

Pretty sure mine has the same problem. It's a March build. The noise is noticeable after it's been sitting for a short while after being driven and restarted. It isn't as audible outside the car, but you can hear it under the passenger dash inside the car. My 2022 didn't make this noise.

It goes away after the car has been driven. I'm taking the car to the dealer tomorrow morning with a printout of the TSB.

[triggerjerk]

Originally Posted by DangerZL1

Pretty sure mine has the same problem. It's a March build. The noise is noticeable after it's been sitting for a short while after being driven and restarted. It isn't as audible outside the car, but you can hear it under the passenger dash inside the car. My 2022 didn't make this noise.

It goes away after the car has been driven. I'm taking the car to the dealer tomorrow morning with a printout of the TSB.

Any update?

[DangerZL1]

The service advisor wants to make sure he has a tech available. I’m going to call him early Tuesday morning and I’ll bring it in if he can get someone to look at it. I have the TSB printed out. Hopefully I can get them to hear it and I’ll update afterwards.

[Blueclyde]

This is all very interesting. I have a 23 ZLE that was manufactured in April of 23. Mine started making the noise down at Camarofest with about 1100 miles on it. I isolated the noise to something under the passenger compartment floor. I could actually feel something tapping on the rear passenger floor. I took a peak under there yesterday and noticed the fuel tank and a couple lines. I’ll be looking into this further when I perform a fluid change.

[DangerZL1]

I was able to clearly hear the rattling with my stethoscope last night. It's pretty loud just laying the probe on the braded line at the rear of the engine, just as described in the TSB.

I took my car in for the noise this morning and had a printout of the TSB with me. The service advisor pulled it up in his system. I noticed the model year range for the Camaro is now 2016-2023 and the date at the top is July 18th.

The tech didn't hear the noise very well, but was able to feel the vibration in the fuel line. I think he had some other techs look at it and said it shouldn't be doing this. They're ordering the fuel line. It's not the same part in the pic on the TSB and goes to the rear of the car near the fuel tank. The part number is 84404473, but as already mentioned is on backorder.

[triggerjerk]

Originally Posted by DangerZL1

I was able to clearly hear the rattling with my stethoscope last night. It's pretty loud just laying the probe on the braded line at the rear of the engine, just as described in the TSB.

I took my car in for the noise this morning and had a printout of the TSB with me. The service advisor pulled it up in his system. I noticed the model year range for the Camaro is now 2016-2023 and the date at the top is July 18th.

The tech didn't hear the noise very well, but was able to feel the vibration in the fuel line. I think he had some other techs look at it and said it shouldn't be doing this. They're ordering the fuel line. It's not the same part in the pic on the TSB and goes to the rear of the car near the fuel tank. The part number is 84404473, but as already mentioned is on backorder.

Thanks for the update. I still haven't heard back from my dealer on the part status.
Edit: just heard back. Part is in. They are saying the tsb part number is 12663577.
Edit 2. I gave both pns to service writer. He and tech think either could be the issue and the tsb isn't clear. They are going to instal 12663577 next thursday first and try 84404437 if that doesn't work. I can't believe there isn't clarification on this.

[WhiteMale]

https://www.amazon.com/ACDelco-12663.../dp/B014REZ0ZO

https://www.rockauto.com/en/parts/ac...e+/+hose,11224

[DangerZL1]

Originally Posted by triggerjerk

Thanks for the update. I still haven't heard back from my dealer on the part status.
Edit: just heard back. Part is in. They are saying the tsb part number is 12663577.
Edit 2. I gave both pns to service writer. He and tech think either could be the issue and the tsb isn't clear. They are going to instal 12663577 next thursday first and try 84404437 if that doesn't work. I can't believe there isn't clarification on this.

Thank you. Please keep us posted on the repair. My advisor was also surprised at the lack of clarity. I don't see a check valve in part number 12663577 in the pic.

I'll refer to this post if your repair is successful. Good luck!!

[Laidoffsick]

Originally Posted by WhiteMale

SO this isn't a line rattling, it's more complex than that...right?

Its not a rattle. It's a ticking sound from the fluctuating fuel pressure caused by a crimp in the fuel line during assembly. GM has know about it for several years and it's due to them having 2 different part numbers for the same fuel line. One of them is a tad too long, so when it's connected during assembly it gets bent just enough to be a problem. Not major but the sound is very irritating and you will notice a bit of hesitation when you get on the gas real hard.

I noticed my car had it from the day I took delivery of it with 2 miles on it. The dealer put it on the rack and first told me it was normal due to the high pressure fuel pump. A friend has a ZL1 one year older than mine and he never had that noise. Then I was told it was just a rattle, the fuel line rubbing against the frame. Then I was told it was an exhaust leak and it did sound like one.

Finally after getting all the managers involved at the dealership, the suddenly discovered the service advisory that GM had put out a year or two prior.

1st they sent the fuel line for an SS so we had another delay. Finally got the right part and problem solved. Total... 2 months and this is how they returned my car after the first 6 weeks of having it.