Hey guys, I'm new here and need some info on changing the plugs on my 98 f150, 4.6.
I've read as much as i could find in the archives.
Everyone seems to indicate Motorcraft plugs are the only ones to use. I've already bought some Autolite double platinums. I only want to do this once as i can see its going to be a PITA. Why only Motorcraft?
Oh for my old 4.9l and an easy engine to work on.
Thanks,
LJ

 

Welcome to the site...

i tried autolights in my old 4.6...and never had any luck with them...started using motocraft never had another problem with them..

 

My '94 Lincoln TC, 4.6L/AODE needed some plugs to replace the original Motorcraft items so I tried some Autolite platinums. Performance was OK, but had some anomalies I didn't like.

I then decided to take up Bosch on its boast that their P+2 plugs would provide better fuel mileage and/or performance or your money back. That was 30K miles ago. The plugs are still in there.

Fuel mileage went up about 5% accompanied by a definite improvement in engine smoothness....very important in a Lincoln luxo-boat.

Now, the Lincoln of that year has the EDIS-8 ignition system that fires two plugs in series. The plugs in cylinders 1-4 fire at reverse polarity and tend to erode the ground electrodes of the plugs. Ford plugs for the application have special plugs for 1-4 that have platinum-loaded ground electrodes so that they will last 'til the 100K changeout. Double platinum plugs can go anywhere, EDIS-X or COP. The Bosch P+2 plugs do not have platinum-loaded ground electrodes, so at 30K I pulled number one plug to check...the ground electrodes appeared as new.

COP systems don't require special plugs in any position.

 

Finally changed the plugs out today. Ah - for the good old days when thing were reachable. #4 was a bear. Hardest part all around was getting the boots off. Seems like the engineer could have angled the plugs toward the front instead of the back. WD-40 sprayed down along the boot seemed to help to get them out. A piece of tubing to get the plugs out and in was invaluable. Taped the socket to the first extension so it wouldn't come off.
I only ever want to do this once.
Thanks for your help and input.
LJ