Gotta change plugs

[BirchMarauder]

are these plugs ( http://www.summitracing.com/parts/NGK-3403/) the ones to go with. only have DR tune, K&N, no other mods. was gonna get upgraded ropes as well. Thanks

[fastblackmerc]

are these plugs ( http://www.summitracing.com/parts/NGK-3403/) the ones to go with. only have DR tune, K&N, no other mods. was gonna get upgraded ropes as well. Thanks

What are "ropes"?

Here is a list of all the plugs that will fit a Marauder:

Spark Plugs:
Stock Heat range
Autolite –104
Autolite Double Platinum – APP104
Autolite Iridium / Xtreme Performance – XP104
Champion Copper Plus – RS12YC
Champion Platinum Power – 3401
Champion Double Platinum – 7963
Champion Iridium – 9204
Bosch – BSH7571
Bosch Platinum – BSH4205
Bosch Platinum+2 – BSH4305
Bosch Platinum+4 – BSH4458
NGK V Power – TR55
NGK G Power Platinum – TR55GP
NGK Laser Platinum – PTR5C-13
NGK Irdium IX – TR55IX
AC Delco – R42LTS6
AC Delco Platinum – 41810

Colder Heat range
Spark Plugs:
NGK – TR6 (+1 colder)
Autolite Iridium / Xtreme Performance – XP103 (+1 colder)

I'd stay away from the platinum or iridium plugs.

I use the NGK-TR6 plugs in my MM. These can be picked up at any FLAPS.

[BirchMarauder]

The connectors

[Siege]

OEM coils are the best so unless you have a bad one then keep them.

I have seen a few posts where people have said that DR's tune is meant to be run with one step colder plugs due to increased timing advance. You should confirm that before deciding on plugs.

[DOOM]

Motorcraft sp-505

[fastblackmerc]

OEM coils are the best so unless you have a bad one then keep them.

I have seen a few posts where people have said that DR's tune is meant to be run with one step colder plugs due to increased timing advance. You should confirm that before deciding on plugs.

Only if you requested a tune with colder thermostat & plugs.

[Baconbit]

I hate to add to an old thread but are regular Bosch Platinum spark plugs any good in our car? I know motorcraft and NGK are good but are the Bosch alright?

[Blackened300a]

I hate to add to an old thread but are regular Bosch Platinum spark plugs any good in our car? I know motorcraft and NGK are good but are the Bosch alright?

Its been confirmed that Bosch are crap. Run Motorcraft or NGK's

[MOTOWN]

Its been confirmed that Bosch are crap. Run Motorcraft or NGK's

Im currently running Bosch irridium plugs with no problems, and ive used there plugs for years!

[marauder410]

im actually running the bosch irridum plugs also and havent had a problem but next time im changing plugs gonna go with the motorcraft plugs since theres been nothing but good things said about them

but the bosch plugs im running have been just fine

[greggash]

I am running autolite 103's gapped at .028
for a vortech supercharged application.
With Accell COPs....runs perfect at all speeds

[BirchMarauder]

what am I supposed to be gapping my new NGK plugs at. I'm NA. NGK says .052 is this correct? or should I close it in somemore. Thanks

[fastblackmerc]

what am I supposed to be gapping my new NGK plugs at. I'm NA. NGK says .052 is this correct? or should I close it in somemore. Thanks

I always gap my plugs at the lowest end of the range so as the electrodes wear they will always be in range.

[BirchMarauder]

thanks FBM thats helpful but I was looking for a number tho. should I stick with .052 or go lower like .048? let me know. thanks for the help. google isn't my friend today and won't let me find what oem gap is.

[tbone]

Its been confirmed that Bosch are crap. Run Motorcraft or NGK's

I have Bosch in my car right now and it purrs like a kitten. Silky smooth idle, ferocious WOT.

[tbone]

I use the NGK-TR6 plugs in my MM. These can be picked up at any FLAPS.

I took your advice and ordered these up to go with my 180 t-stat. What do you gap yours at to start? .048?

[fastblackmerc]

I took your advice and ordered these up to go with my 180 t-stat. What do you gap yours at to start? .048?

I believe the factory range is .052 - .056

I set mine as close to the lower number as possible.

[tbone]

I thought it was 048 to 052?

[fastblackmerc]

I thought it was 048 to 052?

Nope...

Looking at the Ford Shop Manual "0.052 0 0.056 in" or 1.32 - 1.42 mm".

BTW... same specs for a 2v motor.

[ctrlraven]

I ran NGK TR6IX plugs while on DR's tune, no problems. Still run them today as well. Only problem with the IX series plugs is you can not gap them so if you go to a store and buy them have a gap checker with you can check them right there. Some may be .035-.037 range, I've been lucky to get all .036 gapped ones but I have came across a few .035 before.

The GMS coil connectors are a wise idea to do when you do plugs as well, make sure you use a lot of dielectric grease on the contacts, not globs of it but covered well.

[Siege]

Should I gap my Iridium Plugs?

The manufacturers say NO.
This is because most people do not know how to properly gap a spark plug, and the center electrodes on the ultra-fine iridium can easily snap if mishandled. There is no warranty for snapped center electrodes. The manufacturers say an iridium spark plug will run so much better than a traditional plug, even if it is not gapped for that motor, that they would prefer you just leave it rather than risk snapping the center electrode.
Personally, we at sparkplugs.com, gap our iridium plugs for our own vehicles (we’re rebels). If you insist on gapping your iridium plug, please refer to Proper Gapping for instruction.

This was a response to a message from tbone asking why the plugs couldn't be gapped. No idea why he deleted his post but I'll leave this here in case anyone else has the same question.

[ctrlraven]

Only reason I went with Iridium plugs was that I do a lot of highway driving and not so much racing so instead of changing plugs every 10, 15k and so on I change mine about every 60-70k miles. NGK says the Iridium plugs are good for 80-100k miles, if you drive spiritedly then you should change them around 60k.

That is true you can gap them but unless you know how to properly gap it I wouldn't even try, the Iridium electrode is super fine and slightest wrong movement and you'll be shouting a whole bunch of potty mouth words and have to order another.

Last time I bought NGKTR6IX plugs I think I paid around $55-60 for 8.

[fastblackmerc]

I buy the plain NGK-TR6 plugs and change them once a year regardless of the mileage. Cheap insurance and I know how my engine is performing.

[TFB]

I buy the plain NGK-TR6 plugs and change them once a year regardless of the mileage. Cheap insurance and I know how my engine is performing.

You could do same by gaping at .048-.050 and running them at least 25K mi, save wear & tear on the threads in the heads...

[fastblackmerc]

You could do same by gaping at .048-.050 and running them at least 25K mi, save wear & tear on the threads in the heads...

I religiously use anti-seize and the proper torque.

[TFB]

I religiously use anti-seize and the proper torque.
Ford says not to use anti-seize but I do as well...

I've heard the claim that anti-seize will skew the torque readings and cause plugs to be tighter than without, I mostly consider that a scare tactic...

Both my 2v 4.6 are at 50K mi, sometime this spring they'll get the factory recommended plugs gaped .002 to .003 closer than spec... They still run fine and gas mileage is as good as it ever has been, but by 50-60Kmi gaps are generally a little wide... Wide gaps are what kills the coils...

[RF Overlord]

Since anti-seize is a lubricant, and the Ford torque specs are for dry threads, using it *can* cause over-tightening, especially if you don't use a torque wrench. I've read that lowering the torque wrench setting by 10% will offset this, so I use 10 ft/lbs with anti-seize and I use just a VERY little on the threads.

[Siege]

I installed my NGK's dry and torqued them to the factory spec.

Per NGK:

NGK recommends only using spark plugs with metal plating on all aluminum head applications to prevent damage to the head and plug. Metal shell plating acts as a “lubricant” which breaks away from the main body of the spark plug during removal, preventing damage to the spark plug and or threads in the cylinder head.

This information can be accessed here: http://www.ngksparkplugs.com/pdf/tb-0630111antisieze.pdf

[bolsen]

How hard is it to change the plugs?

[ctrlraven]

How hard is it to change the plugs?
Honestly it's about as easy as replacing the air filter. Remove the intake zip tube, remove both coil covers, unplug the injector harness off each coil, pull the coil and boot out and then you have access to the plugs. If you have stock coils you need to be careful to not stretch them out, if you have GMS coil connectors then it makes it a lot easier. If you have changed plugs before on any other car then the rest of the process is a breeze.


I've never used a torque wrench when I did my plugs, I've always been able to "feel" about the right ft. lbs. torque. I also do my tightening using a certain clock pattern to ensure each plug is done the same and has the same amount of rotations.

[fastblackmerc]

Honestly it's about as easy as replacing the air filter. Remove the intake zip tube, remove both coil covers, unplug the injector harness off each coil, pull the coil and boot out and then you have access to the plugs. If you have stock coils you need to be careful to not stretch them out, if you have GMS coil connectors then it makes it a lot easier. If you have changed plugs before on any other car then the rest of the process is a breeze.


I've never used a torque wrench when I did my plugs, I've always been able to "feel" about the right ft. lbs. torque. I also do my tightening using a certain clock pattern to ensure each plug is done the same and has the same amount of rotations.
What he said +:


Make sure the plugs are gaped.
You may or may not have to take the coil harnesses off.
Blow out any debris in the tubes before taking the plugs out.
Change plugs on a cold engine.
Install the plugs finger tight, then torque to the correct specs. If your not experienced at tightening plugs, use a torques wrench... you don't what to strip the threads in the head. It's a good reason to buy another tool!
Make sure the coil cover gasket in in place and add some silicone to the area where the coil harness goes between the coil cove and cam cover.
Use anti-seize on the plug threads.... a little dab will do ya!
Use silicone dielectric grease inside the coil boot before installing on the plug.... a little dab will do ya!

[BirchMarauder]

What's the dry torque specs for the plugs? I saw 10 foot lbs with anti sieze but....

[fastblackmerc]

15Nm or 11Ft lbs.

Shop manual makes no mention of wet or dry specs.

I've always done mine to the specs with anti-seize. Over 70k trouble free miles.