2007 navigator with 160000 miles exhibit engine issues, it will move at 55miles on 2007 Lincoln Navigator

but will shake and lose power at rest or light

Asked by for the 2007 Lincoln Navigator
Vacuum leak, low compression on one or more cylinders or misfire. Light on?
yes enhgine light is on , its been seen by three mechanics for $480.00 and all of them is pointing to a engine