What's the best spark plugs to put in a 99 ford expedition 4.6

SOURCE: changing spark plugs

Changing the spark plugs on a 1997 Ford Expedition 5.4L engine takes patience. Remember to start this project on a cold engine! I started on the passenger side by locating the Coil over iginition coils and cleaned out all the old dirt using some compressed air. Then I had to disconnect the electrical connections to both the Coil over ignition coils and the passenger side fuel injectors. Once you remove the small bolt which holds the ignition coil in place, use your compressed air again to blow out the spark plug hole. After that, you will need a 5/8" swivel spark plug socket and various length extensions to remove the spark plugs. Take your time because there is not much room for your hands. Before installing the new plug, check the gap and use clean engine oil on the new threads. Tighten the new spark plug and reinstall the coil over ignition coil. Reconnect the electrical connection to both the ignition coil and the fuel injector. Continue these steps with all eight spark plugs. You will find the ones on the drivers side are difficult because of the fuel rail gets in your way. Have patience and use swivel extensions to work around the tight spaces. When you are done, you will have saved lots of money! Don't forget to replace your air filter, fuel filter, and pcv valve to complete your tune up.

SOURCE: 2001 ford expedition spark plug location

That's because they are hidden quite well. If you look at the engine, you'll see yellow plastic prongs (?) that look like spark plugs, but hook up to the silver tubing.  That's the fuel injectors.  BUT, right behind the yellow plugs, are black ones.  The black one is the connector to the spark plug.  The plug itself sits about 4 inches down into the block of the engine.  They are a real pain, and from what I can tell, you only have decent access to the first 2-4 of them, then they get too far back and start going under the dash (you'll see what I mean when you get there).

Harvey N Tawatao

• 3854 Answers
• Posted on May 24, 2009

SOURCE: spark plug change

There is an individual coil for each cylinder and the spark plugs are located about 5 inches down inside the cylinder heads under each coil. And let's not forget that you need a 7mm 1/4" drive universal socket that costs 50 bucks to get to the 7 and 8 coils, and triple jointed fingers.
It is not an easy job to change plugs on these engines, we usually charge 3 hours labor to change them, it is not a job that the usual vehicle owner can do. I would also suggest you let the dealer change them, they have done many and will save you a lot of pain and time. I always end up bleeding from somewhere after changing plugs on this engine and the plugs are know to break.
Good luck and hope this helps. The plugs are rated up to 100,000 miles and most of the time it's the spark plug boots that go bad and if your getting a miss fire it's a good chance that it may be a Coil to one of the plugs. There should be a DTC code that would indicate if you have any issues with your engine performance.

SOURCE: chaning spark plugs 02 expedition

no special tools,this is what tools you will need:.7mm socket for the coil packs where underneath them is a deep hole and down there is the plugs---8mm socket for the fuel rail bolts(for the left side sitting in it)which i would use 1/4 inch drive for these--- 5/8 plug socket---6 inch extension---3 inch extension---ratchet---swivel---which i would use 3/8 inch drive for these---and maybe long needle-nose pliers incase the rubber boot from the coil packs come off and sticks to the plug.

ZJ Limited

• 17989 Answers
• Posted on Apr 20, 2010

SOURCE: removed spark plug wirers need firing order Ford Expedition 1999

Several engine sizes there...

1999 Ford Expedition 4.6 liter SOHC V-8 VIN "6"





1999 Ford Expedition 4.6 liter SOHC V-8 VIN "W"





1999 Ford Expedition 5.4 liter SOHC V-8 VIN "L"




Hope this help to solve it (remmeber comment and rated this).