My Navigator has been at the dealer for a couple of weeks not due to the same noise and VCT Solenoid (Variable Cam Timing) replacement. I was told the parts are on backorder until the end of September. Something about Lincoln not releasing the parts. I"m wondering if they're doing a re-design or something as others are experiencing the same issue. When cold starting, it sounded like a rod knocking and I'm wondering how much metal was created in the oil from that. We'll see how it turns out.