Are the 6.6 l8t engines inherently noisy?

[chris21]

On 5/16/2024 at 10:52 AM, UWSkier said:

I'm wondering if mine is chirping from the same area.  I started the truck with the hood open yesterday and it actually sounds like the sound is coming from underneath and towards the rear of the engine compartment.

Did you ever find the source of the chirp under light acceleration? I am having a similar sound in my 2025 2500 with 3000 miles, with light acceleration between 30-40 mph and only when the engine has a little bit of load. I thought it was coming from the rear end, dealer said they didn't hear it, then after a second drive they said it was my truck cap whistling... but it is a chirp that clearly only happens under light engine load. I added fluid to the rear diff as it was a bit over half a quart low (same dealer said level was fine,  took over a half quart to bring it up to 1/2" below the fill threads) it still made the noise after that.

[GMCustomerService]

On 5/10/2025 at 11:29 AM, chris21 said:

Did you ever find the source of the chirp under light acceleration? I am having a similar sound in my 2025 2500 with 3000 miles, with light acceleration between 30-40 mph and only when the engine has a little bit of load. I thought it was coming from the rear end, dealer said they didn't hear it, then after a second drive they said it was my truck cap whistling... but it is a chirp that clearly only happens under light engine load. I added fluid to the rear diff as it was a bit over half a quart low (same dealer said level was fine,  took over a half quart to bring it up to 1/2" below the fill threads) it still made the noise after that.

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[UWSkier]

On 5/10/2025 at 9:29 AM, chris21 said:

Did you ever find the source of the chirp under light acceleration? I am having a similar sound in my 2025 2500 with 3000 miles, with light acceleration between 30-40 mph and only when the engine has a little bit of load. I thought it was coming from the rear end, dealer said they didn't hear it, then after a second drive they said it was my truck cap whistling... but it is a chirp that clearly only happens under light engine load. I added fluid to the rear diff as it was a bit over half a quart low (same dealer said level was fine,  took over a half quart to bring it up to 1/2" below the fill threads) it still made the noise after that.

nope.  Still doing it at 20k miles.  Not getting any worse.

[AT4X Steve]

On 5/12/2025 at 6:14 PM, UWSkier said:

nope.  Still doing it at 20k miles.  Not getting any worse.

Mine has the same noises as you have described...slight chirp and the normal fuel injection tick.   Dealer has looked at it twice and said it is not an issue and is normal.   It is not getting worse just annoying for a new truck.  Otherwise I love the 6.6gas