Hi there ! I need to change the spark plugs on my 2005 Freestar 4.2L. The front ones seem to be pretty easy, but the back ones look like to be much harder. How can I change them ?

 

The easiest way to replace the rear plugs is to remove the upper and l;ower cowling assemblies. Don't forget to plug your wiper motor nack in when re-assembling (Been there...Done that )

1. Remove both wiper arms.
2. remove upper (outer cowl)
3. Unbolt lower cowl
4. Unplug wiper assembly
5. Unhook washer hose.

There's your rear plugs.

If you have 75,000+ miles and not done before, may I suggest also replacing the coil pack. These have been known to cause slight mis-fires after this mileage and will keep you from having to remove the cowls again to replace. That will be your call though.

I would also recommend while you're at it, a new set of OEM wires and dielectrical grease on the boot ends to eliminate any spark leakage.

I prefer iridium plugs as they take less energy to fire and is a lot less demanding on the ignition system.

I also use Permatex copper anti-sieze on spark plugs. The aluminum ant-sieze tends to set up from the high temp enviroment.

 

I concur with the 'how to' offered by common sense; the advise offered to me by a Ford tech was to stick with motorcraft plugs and only replace wires and coil if damaged or in the case of the coil, it quits working. These things get changed far more often than really needed but if you are so inclined go for it.

One thing to consider is inspecting for oil leaks around the valve covers; especially the back one. Its a bit of a pain to change so you might as well do it if needed while you have the back all opened up.

 

You need to be careful prying up the plastic cowl in a couple of spots. You can get underneath it with a long screwdriver and pop the the plastic clips out without breaking them.