Chrisgreenm

I was told it has hollowed out cats already. Downstream o2s throw codes and it sounds a little more aggressive so I believe it. I'll still go smack it while it's running and see if that changes anything

Anyone have any ideas what could be rattling around? I've checked it over and over and I don't see anything. Maybe it warped something like my exhaust? Did hit the puddle right after coming off the highway so it was definitely hot

So I finally got around to pulling the manifold. There was a decent bit of water in there mixed with oil. Got it all out and dried it, reinstalled and the noise is still there.

Up until the throttle yes, I didn't go further than that. Would it get past the throttle and stay there?

Without the filter it makes the same noise

I do have codes like p300 and lean fuel on bank 1 but I had that before. No new codes. I pulled the tube off from the box to the throttle, should I pull the throttle and intake manifold too? Maybe waters stuck in the manifold and causing noise?

Oil is clean. Changed it a little bit before the incident and it's still clear clean looking oil, not milky.

I own a 2006 sierra denali with the 6.0 gas. A few days ago I drove through a pretty deep puddle (I know the danger now) and immediately after my engine started knocking. It never stalled, never died or stumbled while in the water. I pulled my intake and it was full of water, filter was soaked. I let it dry while I worked, and let the filter sit in the sun for a bit. Put it all back together and on startup and at idle it did not knock. I could even raise the rpm's and it wouldn't. However once I got about 60 seconds into my drive it started again. Same thing today, it didn't do it on startup or revving at idle but once I put it in drive and went it came right back. I know the obvious answer everyone's gonna say is I bent a rod when I hydrolocked a cylinder, but wouldn't that make noise consistently? And raise with rpm's? Looking for if anyone knows any other possible reason as to why it's knocking or what I'm missing here