I have a 2019 3.5 with 90k and i am hearing the noise under the hood and at cold start. Is it safe to drive my truck untill i gat it fixed

 

We can't guess about it without a code or more info.
Do you have a code to support your concern?
Good luck.

 

No, but i worked for ford dealers for 24 years and these things seem to all do it and mine is rattling at cold start like all the rod bearings are out then while normal temerature its got a little more than suttle knock in the motor