2017 GMC Terrain SLE 2.4L auto trans. I replaced the harmonic balancer and the center bolt after finding that the balancer was wobbling with the engine running. Removed the old center bolt the old balancer pulled right off without having to use the puller tool. I'm still getting the same noise and balancer wobbles still. It's almost a scraping and vibrating noise that is not consistent but comes and goes. The noise occurs when sitting idle and driving. I changed my oil today and found no metal shavings in drained oil.
The timing chain is a possibility, but I'd first check the engine accessories - take off the serpentine belt and make sure that you don't have an alternator or tensioner with bad bearings. If that didn't identify the noise, you could get a "mechanics stethoscope" ( $10 at Harbor Freight) and listen to see if it is the chain. Cam bearings, to me, is the least likely source.
