Hello all,

Does anyone out there know the correct Autolite sparkplug to use in a 1997 f150 Supercab 4.6l 5 spd?

I've read APP104 and APP794. Are these the same? What's the difference?

thanks for any help you can provide.

 

First of all,you are taking a chance by running Autolite plugs! I know,I learned the hard way.My truck stumbled,bucked,and the gas mileage dropped very badly when I installed Autolites in mine! Go back with the factory Motorcraft plugs! Your truck will thank you and so will your wallet!

 

NGK irrid.

 

Hello all,

I thought it might be nice to close this story. My auto repair shop heard from the autolite rep.. Apparently, autolite is now recommending the APP104 plug for the 4.6l.

I had a set installed yesterday and the truck ran great for about 3 miles, then it started to buck and hesitate. Took it back to the shop and a few hours and tries later, they found that the new plug on the #8 piston had not sealed and the leaking compression was popping off the plug boot. They obtained a different plug and problem solved. (Does autolite have a quality control problem? This isn't the first I've heard this happening)

My 97 4.6l is now running great and I hope the gas mileage improves as well.

If you're running APP764's might want to consider swapping out to the 104's for a nice boost in HP.

 

I swapped out both motorcraft and
autolite for the Bosch Platinum +2
with the two electrodes and my truck
loves them. I actually got a hair increase
in gas mileage and I check it with every
tank of gas just for ****s and grins so
something positive is going on here.
It's not like multiple electrodes are new
we have used them for decades on
aicraft engines. So that's my two cents
worth on it .

 

I used the standard Bosch platinums in my truck. I won't use them again though because they made my truck run like crap and set off the CEL. I'm just going to stick with the Motorcrafts from now on.

 

I changed my plugs and wires 3500 miles ago using Autolite APP104'S. The truck had 112,000 miles at the time and it's been running much better every since. Smoother with more power. The mileage went back up to 16 in town (same as when it was new) I beleive the wires should be done at the same time as the plugs, by the time you get done pulling on those wires there's going to be a break in them somewhere. 1998 4.6L F150

 

Bosch sucks big time in Fords.

Save money and stick with Autolite or Motorcraft. ir. plugs are a waste of money if you are not modified IMO. If you want NGK makes a good ir. plug if you have to have ir. Denso is great, but expensive.