I am going to change my plugs in my 99 this weekend. I was hoping someone had a few tips to lead me in the right direction. They want almost $300 at Cowboy Motors (Jackson Hole,WY), so I would love to save the cash and do it on my own. Thanks Rob

 

There are no tricks, really, unless you're talking about getting to them and there's no help there unless you want to remove the hood - which I don't suggest.
From the Workshop Manual:
(1) Disconnect wiring from coil (COP)
(2) Remove the bolt, then the coil.
(3) Blow out all debris from plug well (cavity) with compressed air
(4) Remove plug
(5) Inspect plug for bridged gap
* Check for deposit buildup closing the gap
--- caused by oil or carbon fouling
# oil fouling = wet, black deposits from bad rings or valves
# carbon fouling = black, dry fluffy carbon deposits from incorrect heat range on plug, dirty air filter, too rich fuel mixture or excessive idling
(6) Inspect plug for pre-ignition
* Identified by melted electrodes and possibly blistered insulator, which may be caused by incorrect ignition timing, wrong type fuel, heli-coil installation (I am assuming they mean installed wrong, here.)
(7) Check gap on new plug to ensure .052" to .056" tolerance.
(8) Added Install new plug with anti-seize compound (not too liberally, but enough to coat each and every thread surface.)
(9) Tighten to 7 to 14 lb/ft ( I would suggest 14 )
(10) Added Coat coil contact and boot seal with di-electric grease
(11) Install coil and tighten bolt to 44 to 52 lb/in
(12) Reconnect coil wiring.

 

Biggest trick I learned is that on the last plug on the passenger side (the biggest PITA) is to disconnect the coolant line that runs across the top of the COP. By doing this it makes access to the plug much more manageable. Also you're gonna need a long 3/8" extension, think-10" or better. Make sure to place something under the coolant line to catch the runoff. Also use compressed air once the COP's are pulled to blow out all the dirt that is sure to be in the socket. Good luck, take your time, and get ready to be sore the next day. Later, Judd

 

This is NOT a three beer job. Do it in a cool area, and when you are healthy and fresh.

Do the hard one first. Then congratulate yourself, take a break, shake it off and the others are pretty much a breez. You will end up with a much better attitude.

If you reverse this order and end up on the far back passenger one, you will cuss the ancestry of every Frod engineer that ever lived. I am 49 and have changed hundreds of plugs over the years. I learned this lesson the hard way! DOH!

I put many layers of heavy furniture moving quilts over fender and top of engine area so I could lean across areas without too much pain to me or damage to engine components and stuff.

I made a air chuck extension out of 1/4 inch copper tubing to bend into the spark plud areas to get all the sand and crud out. DO NOT blow any hole if you have a plug out. There is a lot of crap that will fall back into any open holes!

Make sure your plug socket has the rubber plug holder in place and that it holds the plug.

Inspect, under a good light, each and every coil pack and it's electrical connector for corroded contacts and clean them before reinstall.

With anti sieze.... more is NOT better! I use a small disposable acid brush and ensure that all the threads are coated but any excess is wiped clear.

Same with the dielectric grease, just a little will do. I don't know where the automotive guys are getting it, I am a Ham radio operator so I order it from one of my radio outlets. Don't remember ever seeing it in auto parts stores but then again I have never deliberatly looked for it there.

 

A good trick I use is to unplug the fuel injectors,and turn them out of the way.
They will turn with out hurting them and it makes it easier to turn the extension
buy hand. Wich YOU MUST DO! when installing the plugs to avoid cross threading.Other than that all I reccomend is time and patience.

 

Use a length of vacuum hose to start the plug and you will never cross thread them.

 

Dread to think about pulling mine. Just curious to those of you that have changed plugs how many have had problems with bad threads in the head or the threads came out when you removed the plug? If so what did you do to repair the problem, replace head or use helicoil?

 

Don't sweat it. Make up your mind that you're gonna do it, dig in...and do it.

I haven't seen any nor has anyone around this part of the country that have had bad threads. I did take a flashlight and look down into the cavity to make sure, though. All I saw were dry threads where the factory neglected to use anti-seize. But nothing that would indicate weak threads.

But some here have 1st-hand experience. They'll be along shortly.

 

To add some levity to this serious subject, I saw a fellow at the boat fixer one day strip the plug threads in a 75 horse Merc motor... when I saw him repair his screw up with JB weld I waitied around for the owner to alert him... very bad day for that low tech kinda mechanic


I carefully inspected all my holes but the hard one and they were fine also.

Checking plugs is part of my 15K maintenance.

 

Yikes! (: JB Weld! I know that stuff is great for most cases, but holding spark plugs in! LOL Too Funny!

 

Thanks for the procedure list ..Big Orn

 

This may be too late but......

When I bought my used '99 about a month ago I asked the lead mechanic at the Ford dealer about aluminum heads, blown plugs, changing etc. His advice; change the plugs when the engine is at ambient temperature and NEVER when the engine is hot.

 

Garyfdl,

That is always good advice when working with aluminum. But, you should ask him the question "what do we do with the plugs when the owners manual says a 100,000 mile service interval"? Another question should be "what do you guys do when these trucks come in for service. Do they check the plugs" My bet they follow just what the operators manuals says. Don't touch them until 100,000 miles.

 

For the back plug on the pas side use an impact swivel, not a U joint one it looks like a ball joint. Put some black tape around it to keep it on.
Also what ever you do use some anti sieze compound on you plug threads or they will gall to the cylinder and ruin the head! This is the main reasion I cahnge my own plugs on aloy heads because I do not trust the service guys to do it.
Last use a dielectric compound on the plug boot / coil so that next time you can get it off without damage.

 

Roadrunner2

My guess is you're right on both counts. But if you're not having problems why change your plugs out early?

Back in the "old days" I used to change plugs a couple times a year/whenever I did a tune up (I used to have to walk 5 miles to school too, and it was uphill BOTH WAYS!). Mostly 'cause they're cheap and it was (fairly) easy to do. My poor ol' '91 Astro is pushin 225k on the platinum? cadmium? or unobtainium (whatever) plugs, and I can't remember when I last changed them (I'm old but I have changed them because I remember it's a real PITA)