Spark plug replacement on 5.4L V8
 

I've got a '99 F150 with just shy of 60k miles on it. I'm pretty sure the spark plugs need to be replaced as it was running roughly and gave the P0304 code yesterday for cylinder 4 misfire.

It looks like a PITA to change myself, so I took it to a mechanic. All was fine until they called me back and said they had made an error and that the plugs were $18 per spark plug. They're suggesting that the only plug I can use is the NGK 6579 plug. I called Pep Boys and Autozone and Kragen who all suggested Autolite Extreme Performance plugs that run around $6 instead. Who should I trust??? I need to make a decision soon as the truck is at the mechanics right now (although I asked them to hold off until I decide what to do). Thanks!!

The $18 plug is for the 2004 up 5.4. Find out what they will charge you if you take them the plugs.

Put Motorcraft plugs in it!

Phil

they seemed open to me bringing in plugs - but I felt silly bringing parts to a mechanic.

Looks like several people are using NGK's in the Lightening edition - maybe they just confused the motors when looking things up?

Yea, after searching the forums it looks like Motorcraft plugs are more popular anyway.

the lightnings use NGK's because they have boost. motor craft plugs will be the best. or Autolites...didnt ford own autolite?

From the Autolite web site:

Since its inception, Autolite has guaranteed aftermarket and Original Equipment customers worldwide the highest quality products for high performance sparkplugs and sparkplug wires. The Autolite team manufactures Autolite® branded spark plugs and ignition wire sets, and provides plugs to leading Original Equipment Manufacturers like Ford Motor Company and General Motors.

My take on this is, they make Motorcraft plugs for Ford.

Thanks everyone

I'm going with the motorcraft plugs - Thankfully Autozone has them in stock. Seems like most people prefer the motorcraft plugs to Autolite (same company? etc whatever). But it's not bad that the plugs are so cheap right? I think they're only $3.10 each.... hopefully that's ok. Either way it's not happening until tomorrow as I don't have the time to do it right now.

That sums it up alright -

Yea , Honeywell makes both Autolites and Motorcraft plugs. Motorcraft plugs are maunfactured to FORD's strick specifications. Autolites are not.. I tried Autolites once, they lasted 40 miles, I wrote them a letter and they basically said what I have above.

I tried Bosch as well - The truck didn't make it out of the shop.

You don't have to learn the hard way - I already did that, many moons ago :thumbsup:


This may help as well -

https://www.f150online.com/forums/li...parkplugs.html


Don't foget the dielectric grease - very important!!

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If you don't want to use the OEM Motorcrafts for whatever reason, use Denso Iridiums.