I have a 2018 f150 5.0L V8 with 63,000 miles. My local Ford dealer says I need a new time changing guide and cam phaser. My question to you all is how will this affect the longevity of the motor. Considering selling it. I started hearing this rattling noise around 20,000 miles and they said their was nothing wrong with it at that time. I worry I have been driving with one of them damaged a long time. Looking for advice/opinions. Thanks.