Spark Plugs

[04V6Stang]

Hello everyone, I'm new here to the site and have a question. Most likely the first of many!!! Just purchased a 2004 V-6, auto with 105K. Lot of miles, but the car is in really nice shape. Going to start out with some routine maintenance including new air and fuel filters, oil change and new plugs. Someone has told me that the plug threads can easily be stripped since they are aluminum and even more so because of the high miles. True? If so, any tips or tricks to prevent it from happening? The repair manual says to make sure the engine is cool before removing the plugs and to use anti-seize on the threads of the new plugs. Any other thoughts? Thanks in advance for your replies.

 

[STREETLEGAL]

As long as you wait till the engine is cool to the touch to begin removing them you shouldn't have any problems with this engine. If by chance you do find a couple plugs that are being stubborn try loosening them a 1/8th to a 1/4 turn then spray some penetrating lubricant into the plug well and let it sit for about 15 minutes and try again. Repeat as neccesary.

If some of the plugs were hard to come out then it will also be a good idea to purchase a spark plug thread chaser. You'll run the chaser down the plug hole to clean the threads and remove any built up carbon or debris. Then install the new plugs BY HAND until seated, (this prevents the cross threading) then rotate them with the wrench another 1/16, or if you have a torque wrench you'll tighten to about 15lb-ft.

Also if you use a high quality plug like an NGK you won't need to use anti-seize because the plug already has a nickel plating thats designed to prevent siezure to the head. In my 99 GT vert I've always used NGK's and had good luck with them. I found some of this info from their website page on plug installation:

http://ngksparkplugs.com/tech_support/spark_plugs/installation/index.asp?mode=nml

-Brandon

 

[Aeroman]

NGK seem to work well enough, but also Motorcraft & Autolites are the plugs designed for the engine, hard to beat for longevity. Don't use Bosch!
To add to the above good advice, if you have an airline, slacken the threads 1 turn & then blow the thread wells clean before removing the plugs ,this will stop any debris falling into the cylinders & damaging the engine.

 

[04V6Stang]

Thanks for all the good info. I did buy a set of Autolites to install, but think that I better get an inch pound torque wrench for this job.

 

[STREETLEGAL]

NGK seem to work well enough, but also Motorcraft & Autolites are the plugs designed for the engine, hard to beat for longevity. Don't use Bosch!
To add to the above good advice, if you have an airline, slacken the threads 1 turn & then blow the thread wells clean before removing the plugs ,this will stop any debris falling into the cylinders & damaging the engine.

Good advice on blowing out the plug well.

An interesting point most don't know is that Motorcraft is just a 'Ford' brand (they don't make plugs) that is supplied by NGK, Nippon Denso, and Honeywell (owns the autolite brand).