I have a 2008 Ford Expedition XLT. While changing my spark plugs I didn’t push them down as far as was required therefore on two of them the hook broke off and now it’s making a clacking metal sound. I was told that these pieces could have gotten in my pistons requiring me to check the heads. It was told to me that these pieces could not have gotten in to my pistons because they wouldn’t fit. It was also told to me that the noise is just my timing chain that needs to be replaced. Any advice is greatly appreciated.