2013 Tahoe Lt 5.3 with 155k. Just noticed a ticking/rattling from lower part of engine. I have a constant regular ticking(lifter-rocker-rod…?) you can hear in video, but the new sound is the irregular rattle (most audible at 22-26 sec mark). The rattle will increase with acceleration from a stop but becomes inaudible over 10ish mph- not saying it stops, just can’t hear it over the engine. I changed the upstream 02 sensors a week ago coincidentally. Looking for any advice.
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