Knocking/Clanking noise 2019 6.2 Denali

[SierraKid]

I've had this issue for two months but it has been minimal until recently. While going anywhere above 30mph, at around 1200rpm if I give it about quarter throttle to half throttle i will hear a clanking/knocking noise. I have recorded it with my phone but you are unable to hear it at all. The other day while merging on the highway it made the noise much worse than it ever has. I am wondering if anyone has had this before, I know some of the 3.0 DuraMax guys have had it, but has anyone with the 6.2 had an issue similar to this. I will be taking it to the dealership tomorrow. 

[19 Denali ultimate]

Does it sound more like a bunch or marbles rattling in a tin can?  The way you describe how and when it happens almost sounds like pinging (pre ignition) and it can happen when a lower grade gas is used.  It can also happen if there is a lot of carbon build up in the combustion chamber.  What grade (octane) gas do you use and what driving style do you have?  Do you baby it and use lower octane gas or what?  If it is pinging cause by carbon build up there is several ways to clean it out.  Firstly if you already aren't, use higher octane gas, the 6.2 calls for premium (92 or 94) the higher the better.  You could and should also use some injector cleaner ever 3rd or 5th fuel up.  You could also do a seafoam treatment.  Some people will disagree but I have done this in the past and have never had a problem, just be sure you follow the instructions.  Especially the driving it like you stole it part after it has sat to soak.  good luck.   Let us know what the shop said too.

[SierraKid]

On 9/16/2021 at 2:49 PM, 19 Denali ultimate said:

Does it sound more like a bunch or marbles rattling in a tin can?  The way you describe how and when it happens almost sounds like pinging (pre ignition) and it can happen when a lower grade gas is used.  It can also happen if there is a lot of carbon build up in the combustion chamber.  What grade (octane) gas do you use and what driving style do you have?  Do you baby it and use lower octane gas or what?  If it is pinging cause by carbon build up there is several ways to clean it out.  Firstly if you already aren't, use higher octane gas, the 6.2 calls for premium (92 or 94) the higher the better.  You could and should also use some injector cleaner ever 3rd or 5th fuel up.  You could also do a seafoam treatment.  Some people will disagree but I have done this in the past and have never had a problem, just be sure you follow the instructions.  Especially the driving it like you stole it part after it has sat to soak.  good luck.   Let us know what the shop said too.

I took it to the dealer a few months ago, sorry for the super late reply. But they said it was spark knock and to use 93 octane, but I ONLY use 93 and it still did it for a while after. Now it does not do it as much, really weird but glad its mostly gone I guess

[Rob Mugs]

1 hour ago, SierraKid said:

I took it to the dealer a few months ago, sorry for the super late reply. But they said it was spark knock and to use 93 octane, but I ONLY use 93 and it still did it for a while after. Now it does not do it as much, really weird but glad its mostly gone I guess

I've had fuel that I swear wasn't actually 92/93 before.  Stopped going to the station and problem never reared its ugly head again