Changing Spark Plugs

kramer03gt

New Member
Apr 4, 2005
90
0
0
madison, WI
Hey Guys: well it has come to my attention that its time to change the plugs in the 03, So i was wondering if anybody had any tips on the process itself, as far as making it easier and things of that nature or just the process in general, and i am assuming the plenum is going have to come off so im assuming i will need new gasket for atleast that, is there any other gaskets i should think about replaceing or anything else i should maybe look at as a prevenitive maintence type of thing while i am allready going this in depth anyway.


As always thanks guys!!....


Anybody thinking of going to Mustang Week this year?? im about 90 percent in!!!
 
  • Sponsors (?)


No need, the plenum does not have to be removed. Just pulling the intake tubing leading to the throttle body should be sufficient. Do some reading for your method preference of putting the plugs seeing as how our cylinder heads just love to spit plugs out.
 
You don't have to remove the plenum, but just do yourself a favor and remove the TB. It's 4 bolts and takes all of 2 minutes. You can leave the cruise servo cable and throttle cable attached, just pull the return spring off one end first. Puting the TB aside will allow you much easier access to the #2 and #3 COPS and plugs. It can be done with the TB in place, but why bother.

Make sure you blow out the plug wells before you remove a plug. Place a liberal amount of dielectric grease (silicone) up inside the COP contact spring before reseating each COP.

Stock plug gap is .054, although I have found the NGK TR-55's work best with a .050" gap on my car. I would definitely suggest the NGK's. We spent an entire morning one Saturday trying different plugs in my car and even putting it on the dyno, and to say the least, the NGK's made a surprising difference in power and throttle response over the Motorcraft, Denso copper's, Bosch, and Autolite's. Every car is different so just use your own judgement.
 
Have you ever changed plugs before? If not take it a shop. It would stuck to strip the threads. You will also need a 7 or 8mm socket to remove the bolt on each coil. I like copper plugs, as copper is a far better conductor than platinum, plus cheaper. The draw back is copper's life isn't as long. But I like changing plugs. You will need anti-seize. I never put anything in aluminum without it.
 
Anybody thinking of going to Mustang Week this year?? im about 90 percent in!!!


AHHH YEAH!!! I live at Mustang Week, lol.




My tips for changing plugs.

Cold engine, blow out the plug wells, have a telescoping magnet to pull the plug from the well, do not under/overtighten plugs, TB doesnt need to be removed, extensions make the job easy breezy.

Dont fear it, but do keep in mind that our heads are almost prone to blowing plugs.
 
Did my plugs a week ago and it was alot easier to do than i thought. Take your time and dont overtighten. I'll be going back and checking my plugs in a few days to make sure none of them have loosened up or anything due to the amount of people that have recently blown a plug.
 
well i have changed the plugs on my trans am and my lumina z34 but after reading some of these threads there looks to be a little this is a little more involved, so what in the design aspect makes the heads want to blow the plugs??
 
+1 on the ngk's. i tried autolites and motorcrafts and they were no competition to the ngk,s. it's not hard to change the plugs out, just remember to blow out any dust/dirt before you remove the plugs, use some antiseize, don't overtighten, and you are good to go.
 
well i have changed the plugs on my trans am and my lumina z34 but after reading some of these threads there looks to be a little this is a little more involved, so what in the design aspect makes the heads want to blow the plugs??

Due to the design of some of the Ford cylinder heads, there isn't very many threads for the plug to grab onto. There are plenty of threads on the plug itself from the taper to the end of the threads, but half the threads end up poking out the combustion chamber.

Just make sure you get them snug. I wouldn't use anti-seize if I were you, there is no need.
 
Also how is it determined what gap is the best, i noticed the stock gap is .054 but some are using .050, ha i did think there was that much to a spark plug other than taking it out and putting it back in.. its rather intresting.
 
The vast majority of the top selling spark plugs out there today use a metal case/ground strap that is composed of an alloy called nickel alloy N06600. It is very good at resisting any corrosion between the spark plug threads/case taper and the cylinder head threads. This nullifies the need for anti-seize.

Additionally anti-seize, whether metallic or non-metallic, is made from a petroleum or synthetic base. This actually gives the anti-seize a lubricrous property that can exacerbate the problem of the plug being pushed out.

There is only one way to determine which plug gap works best for each application, trial and error. The stock .054" gap is just a recommendation for best fuel economy and emissions, but may not provide the best performance.
 
Understandable.. so is there away to determine gap size with the mods that are on the car??


The tighter the gap the shorter the spark duration, the wider the gap the longer the spark duration. It just all depends on how healthy your COP's are, how much power your are making, and so many other things. If you tighten the gap, it requires less energy to fire the plug, but you are decreasing the spark duration. Consequently, if you open up the gap, it will require more energy to fire the plug, but you are increasing the spark duration.

You just have to play with the gap to see what effect it has. There is always a sweet spot. I always go in .002" increments one way or the other. I've got plug changing on these 2 valves down to about 20 mins or less. :D