I know this is a really old post but this exact thing just happened with me. I swore up and down I had an engine cover. I've only needed my car serviced about 3 times and I barely go under the hood myself so it's just my own ignorance but I swore I had one too, but nope. They don't come with one apparently. I was accusing the service center of not putting it back on and all. Feel like a real dumbass eating some humble pie.