Engine Mechanical problem
2004 Lincoln Navigator 6 cyl Front Wheel Drive Automatic 77000 miles
----------------------------------------------------------------
If you have one coil in a vehicle with 8 coils, how likely will the others go bad if one is bad? Is it better to replace all or some even if just one is bad? What's the most cost efficient thing to do??

I have a linclin with the coil on plug setup, I changed only 2 that were bad and have had no more trouble for almost a year...knock on wood! Change only the bad one...