I recently bought a CPO 2016 F150. FX4,4wd with 3.5 ecoboost and around 30,000 miles. A couple of days ago I noticed a loud banging or clunking noise coming from somewhere in the front engine area. So loud a person standing 30ft or so away can hear it. Only happens within a few seconds of start up going uphill at low rpms. If I step on the throttle it stops immediately but will stop on it’s own with gradual acceleration. Again it only lasts a few seconds but sounds like the engine is coming apart when it does. No other issues or problems of any kind otherwise. Heard about timing chains stretching on these engines but not sure.. any thoughts or help appreciated

Thanks for the input. I have an appointment with the dealership scheduled and taking it in soon. Don’t know if it has anything to do with the problem I’m hearing but didn’t notice any engine noise until I had the sync 3 updated(seriously doubt it). Just hope I don’t get the whole we couldn’t hear anything run around. Guess I’ll keep my fingers crossed.