Newborn’s neck smells

St

Anybody have experience with this? My 3 week old’s neck smells so gross. It is horrible. We bathe him regularly now since his cord fell off but the smell just comes right back. It’s obviously that old formula type of smell. Is there anything I can do or put on it to stop this? We use baby wipes on it when we change his diaper but it doesn’t seem to make any difference.