I need to change the spark plugs on my 1999 5.4l. Is there a trick to getting to the back cylinders since half the engine is up under the dash?

 

use a couple swivels and extensions

 

^+1. I laid out a blanket over the front of the engine bay. You WILL need to remove the fuel rail, so inspect your O-rings at the same time. Take your time, and don't forget to blow out any dirt before removing the plug.

 

I never have removed a fuel rail just worked around it with swivels and extensions and stubby ratchets, chances are you end up screwing more up than your fixing if removing unnecessary items

 

https://www.f150forum.com/f72/97-03-...-change-93389/

 

Got it done, although it took about 5 hours. No need to remove the fuel rail as its easy to work around. Cylinder #4 was a bitch and probably took 1.5 of the hours.

 

Sweet, I've done quite a few at work pretty much go it down to a hour now lol

 

FYI, mine (4.6) took about 4 hours, with the last plug on the passenger side taking the longest, and I DID have to remove the passenger side fuel rail to get at the last 2 on the passenger side. I was prepared with a new bag of O-rings, and one injector needed one where it met the rail. I had regular wires (no COP), and replaced them one at a time, so the length (and location) could be matched up.

4 hours you say? Yes, to also include blasting out each plug chamber with compressed air to keep dirt from entering the head when the plug is removed, plus some additional cleaning of nearby sensors, etc, and a bottle of beer in between as a break.