I have a 1998 F-150 with a 4.6l v8 110,000 miles. When going up hills the engine knocks. The only thing that gets rid of it is high octane fuel. I questioned the guy at advance auto and a customer behind me overheard and told me it was my coil pack. Could this be true? I thought they worked or they didnt.

 

No... Higher octane fuel or retard the timing till its gone

 

One thing to try to help out. Remove EGR and thottle body elbow/neck. Clean the Egr and the port in the throttle elbow completely. Also has your check engine light been coming on?

 

most likely the EGR is not flowing enough. Possible knock sensor, some 4.6's had them, is bad