joshwelsch

I took my 2016 3.5L EcoBoost XLT to Firestone due to a recurring charging system error which resulted in a new alternator. Within a half mile of driving after picking it up I stepped on the gas and as the turbo started spooling I heard what sounded like a foghorn for a moment that goes away and is replaced by a whooshing sound the harder you stay on the gas. If you can get the turbos to just barely engage and keep it at that rpm (~2800) the fog horn sound remains constant. Took it back to firestone and after 4 days they told me they couldn’t figure it out so I brought it home to try myself at which point my check engine light came on as P144C.

I have replaced the blow off valve, carbon canister, and EVAP canister purge valve, all of which were seemingly working before but they seemed like the most likely places to start. I’ve also tested that the waste gates are functioning properly and they are. No visible signs of damaged tubing or oil leaks anywhere.

Does anybody more experienced than me have any suggestions of next things to check/replace?

thanks

joshwelsch

As an update, the sound goes away when the air filter is removed