Topic: Spark Plugs....

[Ceeker]

I had the old AC 41-102  plugs in my car and swapped them out to the AC 41-108.

I did notice a smoother cold idle but that's about all. I run mine pretty hard from time to time but the old 41-102 plugs still looked to be in good shape.

My opinion is stick with the AC 41-108 plugs for now as no one has come up with a better solution. 

[esky]

Anyone has a detail instruction on how to replace the sparkplugs on 2.0L?

[snaponbob]

First, the AC41-108 is the only plug to use in the LNF in the Kappas. Even Lyndon recommends NOT to put anything else in the engine. As for the "instructions" to replace the plugs, it is fairly easy.

1 ) Remove the plastic engine cover.
2 ) There is an acoustic mat that cover the valve cover. The easiest way to do that is to use a razor blade to make a slice in the mat to allow removing it as a wiring harness snakes through a hole in the mat.
3 ) Use a 10mm socket to remove the retainer bolts that hold down the four coils over the plugs. (I forget if the leads to the coils need to be released.)
4 ) Remove the coils.
5 ) R&R the plugs. TORQUE the plugs PROPERLY.
6 ) Install the coils with dielectric grease inside the plug caps.
7 ) I'll let you figure out the rest.  
Close hood.
9)  
10) Then  

[Sky 5]

First, the AC41-108 is the only plug to use in the LNF in the Kappas.
 Even Lyndon recommends NOT to put anything else in the engine.

And a reminder... to help prevent thread stripping the engine should be cold during install,
 not kinda warm, not cool enough to work on;
 but cold as in ambient... room temperature.

[snaponbob]

And a reminder... to help prevent thread stripping the engine should be cold during install,
 not kinda warm, not cool enough to work on;
 but cold as in ambient... room temperature.

YUP!!!!!!!!!!!!   

[jonymac]

Bob - can you explain step 5 and 6?  R&R?  What is the stock torque?  I am a chronic over-torquer...  Inside the caps?  Do you mean on the threads?

[lil goat]

You forgot throw away plastic engine cover that helps retain heat...

[rich71]

i assume r&r is remove and replace. The manual states not to use antiseaze on the threads. Use dielectric grease on the inside of the plug boot so it doesnt cook itself onto the spark plug shaft and make removal at a later date more difficult. I don't have my shop manual here at work so i don't know the torque off hand............ edit - other forum states it should be 15lbs. I am sure someone will chime in to verify

[jonymac]

Cool - thanks - wasn't sure if "R&R the plugs" was some shorthand for a gapping procedure.  Any spec on the gap for the AC41-108s - should this be checked or do they come properly gapped?

[rich71]

the plugs come pre-gapped and are plug and play  - reason being the fragility of the electrode. if you check for consistancy, just be VERY careful not to break the tip of the electrode.

[snaponbob]

i assume r&r is remove and replace. The manual states not to use antiseaze on the threads. Use dielectric grease on the inside of the plug boot so it doesnt cook itself onto the spark plug shaft and make removal at a later date more difficult. I don't have my shop manual here at work so i don't know the torque off hand............ edit - other forum states it should be 15lbs. I am sure someone will chime in to verify

Yes, yes, yes, and yes. And I just did. Plugs should be okay right out of the box.

[Graywolf]

I have used three different spark plugs in my engine that puts out 385rwhp, E3 which fouled out at about 1000 miles , stock plug which worked great, and Ngk ILTRA6A-8G which is the next colder plug and recommended for cars running 100+ hp over stock which is in my car at present. I strongly recommend sticking with the stock plug since I have not seen any performance advantage over the other two plugs.

[tazz]

Stock plug, NGK or Denso but they need to Iridium fine tipped .4mm not any larger on the tip.  Used to be that NGK made the AC spark Plugs since engraved on the side of my stock plug was an NGK #IRTR6C.   

[HAMMER DOWN]

Went to Auto Zone to get new spark plugs. 65K on the original ones. Notice sense the end of last season. I'm down 2.5 mpg on avg. a cross the board.  Their computer calls out AC 41-108, but don't have any. The only plug that they had in stock & that could be cross reference to, is the AC 41-102 = Autolite  XP5263. The only difference is it has .6mm tip, instead of the .4mm tip.
 I'll get them installed later today. Hope mpg goes back to my normal for me. MPG is not really concerns me. I use it more as a tool. When my avg. mpg drops steady 2 to 3 mpg for a couple months. It tells me I have worn, dirty &/or failing part. I already serviced my K&N in April. I inspect & clean my MAP sensor if needed & install my new plugs. Other then that, she runs flawlessly    

Mike

[LatinVenom]

The 41-102 are the original plugs on our 2007 GXP. They are colder than the 41-108 that later appeared on the 2008.
If you can still get the 41-102 I would go with those.

[HAMMER DOWN]

The 41-102 are the original plugs on our 2007 GXP. They are colder than the 41-108 that later appeared on the 2008.
If you can still get the 41-102 I would go with those.

I can't get the AC 41-102. But I did got its equivalent,  Autolite  XP5263.

Not plug & play. Gap out of the box is .048 
Mike

[HAMMER DOWN]

I change my spark plugs, OEM plugs are the AC 41-108. After 65k they gap at .033. I went to a colder plug.  Because I'm running the GMPP tune, with max boost over 23psi. The plug, Autolite  XP5263, equivalent to the AC 41-102.The original plug for the early 07 GXP.

The Autolite  XP5263 is not plug & play. Gap out of the box is .048. I gap then down to .035.

Mike

[LatinVenom]

Thanks good to know.

[tazz]

Yeah I never assume that the gap is correct on any plug even my lawn mower plugs Always check the Gap.

[Kuprito]

I already know what happens with the wrong gap...

I installed the plugs (LTR6IX-11) just out of the box and the car feels like not liking boost.

I think they are .043 (1.1mm) a little bit far than the .035

[Sol Asylum]

If you saw how spark plugs get shipped to your local retailer you would never trust the gap on the plugs, in fact you would probably question if the plugs were any good to begin with.