My 2018 F150 5.0L engine makes a popping noise somewhere in the intake plumbing occasionally. If it was every start-up I'd be more concerned but it pops about every 8th time. I added a cold air intake system hoping that would solve the problem. It did not, although I have better acceleration. On one of the Ford forums someone mentioned that there was an adjustable intake runner valve which could be making that noise. I'd like to know for sure before taking it in to the dealer.