I have a 2011 Lincoln Navigator. There’s an interminttent knocking noise coming from the dashboard and now there’s one coming from the inside back of the car. No one can seem to figure out what it is? Can you help?
The intermittent knocking in the dashboard is likely to be a case of blend doors in the HVAC system that are no longer functioning properly. The knocking in the rear of the vehicle could be something as minor as a loose spare tire/tire jack or something rolling around under the rear seat, or something more serious, such as exhaust components or rear suspension components that are loose.
Bear in mind that noises can be “telegraphed” in such a way that they can sound like they are coming from areas other than where they actually originate.