How to change spark plugs on a 4.2L ? - Ford Forum - Enthusiast Forums for Ford Owners

Thread Tools Search this Thread
Old 01-26-2013, 11:02 PM
Junior Member
Thread Starter
Join Date: Jan 2013
Posts: 1
Default How to change spark plugs on a 4.2L ?

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 ?
Reply With Quote
Old 01-28-2013, 09:32 AM
Senior Member
Join Date: Jan 2007
Location: Yorkshire, NY
Posts: 1,977

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.
Reply With Quote
Old 02-07-2013, 07:32 PM
Junior Member
Join Date: Sep 2012
Posts: 8

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.
Reply With Quote
Old 05-15-2013, 04:24 AM
Junior Member
Join Date: May 2013
Posts: 2

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.
Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Changed spark plugs now No spark No start Rogerseric Ford Econoline E Series 3 08-12-2011 12:34 PM
97 5.4 How to change spark plugs thequif Ford Econoline E Series 1 03-02-2011 01:27 PM
Wires/Plugs/ Coil change quint2 General Tech 1 03-02-2008 02:21 PM
98 Taurus Plugs/Wires - Hard To Change? AbNormal27 Ford Taurus 2 04-03-2006 08:51 PM
E3 Spark plugs reddragon General Tech 1 05-20-2005 02:17 PM

05, 2005, 42, 42l, change, changing, ford, freestar, good, iradium, plug, plugs, rear, replace, replacing, spark

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 02:14 AM.