Are the 6.6 l8t engines inherently noisy?

Dunn · September 2, 2023

Engine is smooth....power steering is a bit noisey

I bet he did think it was a diesel though as mentioned for the over fill

Eric.V · April 4, 2024

I bought my 2024 2500 ZR2 with the 6.6 gas and the first week of ownership at 193 miles it died on me while heading home from dinner. Left me stranded in a turning lane for 5 hours before a big enough flatbed arrived to take the truck home at 2am. Luckily I was already in my neighborhood and not on a busy road. The next day another flat bed took it to the dealership and they found that the whole fuse block on top of the battery was blown. They replaced it and the truck was working fine. Until yesterday afternoon at 830 miles the engine developed a loud knock that would rise with RPM. After noticing it I got on the phone with the dealership to let them know I was driving straight over there. Dealership put me at the front of the list for a loaner due to the circumstances and sent me on my way. Today I heard back from the dealership and they informed me that upon removing the oil pan the tech found chunks of metal. With further inspection they found a spun bearing on the crank. They sent the info to GM and they will be replacing the engine. As of now the turn around time is 2 weeks. Needless to say I am very disappointed with the experience I've had with the new truck. The truck itself is beautiful and rides so smooth with the ZR2 suspension. The Allison transmission shifts amazing. But seems like GM QC was not to par with my particular unit.

Edited April 4, 2024 by Eric.V

Pryme · April 5, 2024

12 hours ago, Eric.V said:

I bought my 2024 2500 ZR2 with the 6.6 gas and the first week of ownership at 193 miles it died on me while heading home from dinner. Left me stranded in a turning lane for 5 hours before a big enough flatbed arrived to take the truck home at 2am. Luckily I was already in my neighborhood and not on a busy road. The next day another flat bed took it to the dealership and they found that the whole fuse block on top of the battery was blown. They replaced it and the truck was working fine. Until yesterday afternoon at 830 miles the engine developed a loud knock that would rise with RPM. After noticing it I got on the phone with the dealership to let them know I was driving straight over there. Dealership put me at the front of the list for a loaner due to the circumstances and sent me on my way. Today I heard back from the dealership and they informed me that upon removing the oil pan the tech found chunks of metal. With further inspection they found a spun bearing on the crank. They sent the info to GM and they will be replacing the engine. As of now the turn around time is 2 weeks. Needless to say I am very disappointed with the experience I've had with the new truck. The truck itself is beautiful and rides so smooth with the ZR2 suspension. The Allison transmission shifts amazing. But seems like GM QC was not to par with my particular unit.

Sorry to hear man this is not good news. Hopefully the new engine will get you going for years to come. This can happen to any brand and does for sure. It’s never fun when it’s our own though. If it’s any consolation, that truck looks awesome. Two week turn around seems really quick at least.

MORSNO · April 5, 2024

My parents bought a new '72 Buick Electra 225 and lost a water pump as they were leaving the lot with it, never had another problem over eleven years of ownership. It happens but doesn't mean it's a lemon.

Edited April 5, 2024 by MORSNO

Eric.V · April 5, 2024

1 hour ago, Pryme said:

Sorry to hear man this is not good news. Hopefully the new engine will get you going for years to come. This can happen to any brand and does for sure. It’s never fun when it’s our own though. If it’s any consolation, that truck looks awesome. Two week turn around seems really quick at least.

Yea I agree with you on that! Just wanted to get this out here in case any one else is going through it with these trucks. They aren't alone!

Eric.V · April 5, 2024

1 hour ago, MORSNO said:

My parents bought a new '72 Buick Electra 225 and lost a water pump as they were leaving the lot with it, never had another problem over eleven years of ownership. It happens but doesn't mean it's a lemon.

Oh man that's terrible! The service team at the dealership seems to be A1 so I'm sure they'll do a great job.

UWSkier · May 14, 2024

This is a lukewarm start, but it's much more noticable on cold start. Hear the chirping sound? I also get it at light throttle applications if I'm coasting around 40 MPH and on and off the gas. Distinct chirping sound that can be heard in the cab. I don't believe it's belt related as engine load seems to make it disappear. Anyone else dealing with similar?

https://photos.app.goo.gl/VTtedVjAzwjzfB3C6

BuckWallace · May 15, 2024

1 hour ago, UWSkier said:

This is a lukewarm start, but it's much more noticable on cold start. Hear the chirping sound? I also get it at light throttle applications if I'm coasting around 40 MPH and on and off the gas. Distinct chirping sound that can be heard in the cab. I don't believe it's belt related as engine load seems to make it disappear. Anyone else dealing with similar?

https://photos.app.goo.gl/VTtedVjAzwjzfB3C6

Might sound weird, but check your exhaust flange connections. I had a whistle when I first bought my truck, but it was only at around 2k RPMs. The dealer was no help, so I crawled under the truck and had my wife rev it up and I found a gap in one of the flanges. It was a pain to tighten it up, but it stopped the sound. Yours sounds more pronounced than mine so it might be something else, but it wouldn't hurt to check.

lineman1234 · May 15, 2024

BuckWallace..

...

By any chance is you pic of the flange the one about mid exhaust system before the muffler??

Although i have a regular cab, and have no noise like being mentioned. I do have water dripping from the muffler hole quit often and quit a bit, as well from the first and or only flange in your pic. I havent thought of tightening it till now, now that you mention. But will tomorrow morning. It was leaking today, and it is noticeable as water coming and dripping from it. I thought it might be normal.

BuckWallace · May 16, 2024

On 5/14/2024 at 6:21 PM, lineman1234 said:

BuckWallace..

...

By any chance is you pic of the flange the one about mid exhaust system before the muffler??

Although i have a regular cab, and have no noise like being mentioned. I do have water dripping from the muffler hole quit often and quit a bit, as well from the first and or only flange in your pic. I havent thought of tightening it till now, now that you mention. But will tomorrow morning. It was leaking today, and it is noticeable as water coming and dripping from it. I thought it might be normal.

The flange with the gap in the picture is right after the exhaust manifold.

UWSkier · May 16, 2024

10 hours ago, BuckWallace said:

The flange with the gap in the picture is right after the exhaust manifold.

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.

BuckWallace · May 16, 2024

8 hours ago, 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.

Could be. Mine only did it around 2k RPMs, but I suppose if the gap is large enough it could do it at idle as well. Could be something totally different, though—good luck!

D Ray · September 1, 2024

I have a 2021 Savana with the 6.6l gas. Heard a ticking noise was told it was normal while under warranty. 137000 miles the tick got louder and number 8 cylinder misfire. Replaced spark plug and coil still misfire. Removed intake manifold and valley plate to find a destroyed cam shaft. GM said to many miles on engine and would not warranty. $13000 new engine installed. 30000 miles new engine misfiring on cylinder 1 put new shark plug and coil on sill misfiring. Also have the ticking back. Back to dealer next week

Tallman3 · March 5, 2025

On 5/10/2023 at 6:56 PM, Jettech1 said:

I can’t seem to get off this quote, but anyway - I’ve got a 21’ 2500 6.6 gas with 108k miles on it. All of a sudden the oil coolant lines failed at the fitting (which I hear is common) but as soon as I picked it up I now have this galloping knock sound. Mechanic took took the belt off, still makes the noise. No codes. Engine runs fine, just this super annoying knock now. I’ve heard these make noise but this is just embarrassing. I’ve linked the Video any thoughts?

lundimpact1775 · March 10, 2025

My 2020 L8T Silverado 2500 is noisy at 98k, has been noisy since I bought it at 89k.

Hpfp failed twice between 89k and 93k, once mechanically and the 2nd time the electronic side of the new hpfp failed. Truck makes ticking noises but it's smooth so idk. Had an independent and very well regarded shop look at it and also had them fix the hpfp, they never mentioned any issues with the noises so I just let it go. I'm do disappointed by GM trucks at this point ignorance is bliss in my world.