New guy here! When I got my wife her 97 EB expedition used, it was in GREAT condition. I simply had my mechanic (bro in law) throw some new, NON motorcraft plugs and wires in the 80,000 mile 4.6 engine, and thought it was good to go. As time went on, we realized that at a stop, it had a bad loping idle to it. Upon further research, my mechanic claims that the ford 4.6 runs very poorly on ANYTHING other than the original Motorcraft wires and plugs. Is there ANY truth to this? The truck runs OK, except for a bit of very light spark knock under moderate acceleration, and the idle issue it has at a stop.

If this is NOT the norm, I think I will remove and clean out the IAC motor, and see if that helps at all with the loping idle.

 

normally I would say no but I have also heard that about fords...

 

motorcraft platinum is the only way to go

 

the 4.6 is very picky about plugs and wires.

Coppers will run best and make the most power.

I like the awsf-22c for a 4.6 mod motor.

Platniums are for people who don't want to change the plugs every 30k, but they are still a good plug as long as they are motorcraft.

Plug wires, stick with OEM motorcraft, the rest are not even close.