My 2017 f150, 3.5L with 102k miles is starting to make soft knocking sound from the engine at idle. I’m not sure if this should be something to be concerned about but maybe the start of a problem! I attached a video audio to hear the sound. Had a tune up done and it is running great.

 

Use a Mechanics Stethoscope without the Probe and see where the noise area is. The handle will pick up sound by itself. Then you can use the Probe to zero in.
It > may be < the High Pressure fuel pump.
Were not that good, just from the sound, outside.
You have to do the detection work.
Good luck.

 

Okay I will try that to pinpoint were exactly it’s coming from. Thanks for advice

 

Second generation 3.5? It sounds too loud to be the High Pressure Fuel Pump.