Alright, got me some Denso IT16's from TP. My 2001 4.6L non-PI says .052 - .056 gap. Denso says these plugs come .044 out of the box. I get .040 on my guages and in searching, other's here have found the same thing. The guys at Denso tech said that their numbers must include the "u groove" in that figure, and per Mike's recommendation to gap at .050, I would have to agree. Does this sound right to everyone else? They were .040 and I gapped them to .050 for a functional gap of .054. Picky I know, but I'm curious....and PICKY!!!

EDIT: *****...I just found one that I haven't even "gapped" yet with a small, but VERY smooth groove in the porcelin. Looks like a factory defect or super perfect "chip" up near the electrode. Think it's alright or? If so, I'll put it in the #1 spot so it's at least "easy" to get to.

 

Took the bad plug to Auto Zone and they swapped me out!!! Great place.

Anyway, my second plug back (factory) on the pass. side looked like it had been dinged on install and was all kinds of messed up. The electrode was bent all the way over to one side of the center electrode and had a gap of .040. The first one on the driver's side was pretty white, the rest were alright looking except for the two rear most driver's side ones were rusty and all of them but the damaged one were gapped between .052 and .056. I have 55K miles.

 

Good deal they replaced it, sounds like a good place.

So did you gap them at .050? I would have done the same think had I came accross this issue.

I remeber I changed mine about 2k miles after I got my truck (about 110k miles) and the gaps were so far off and varied so much it wasnt even funny. Needless to say it seemed to run a lil better after the plug change.


On a side note, you wouldnt happen to have a close up pic of the small WMS tube that goes from the fender to the airbox would ya? I replaced mine with some 3 inch air duct stuff about a year ago, but it falls out of the airbox everyonce in awhile. Id like to find something better and get an idea from that WMS kit. Also if you knew what size it is too, that would be cool. Thanks.

 

Hey man, just got back from the lake. I had WMS keep that piece since my airbox is modified. It only saved me $4 so I guess I should have kept it huh? You should be able to get just that piece from them for $4 plus shipping. If not I'll tell them I want my piece now and that should get it. Before I chopped my airbox I used a 3" - 3" Fernco from Home Depot and secured it on one side with the hose clamp...worked like a charm. I believe WMS's piece is 3" as well. Yeah, I gapped them at .050 because the groove accounts for an additional .004 somehow. I spoke with Denso tech twice Fri. night.

 

BTW, the job only took me 4 - 4 1/2 Hr. taking my sweet @ss time, and I didn't think to start licking (yes, licking) the porclin on the plugs so the damn spark plug socket would let loose till about the 5th. one. It would stay in the hole so I had to fish it out with an extension and hope it would finally work loose before the extension released again. Hahaha...I may be the only one to say it, but I actually enjoyed changing my plugs and now that all the mystery is out of it, will likely do them again at 95,000 mi. along with coil packs and O2 sensors.

 

Cool, thanks for the info. The stuff I have now actually fits inside the airbox instead of over the little nipple thingy.

When I changed mine I did the same thing-after the 4th or 5th one I finally figure a lil spot of oil on the rubber in the socket will work. It drove me crazy when the socket stuck on there.

You probably are the only one that liked to change the plugs on the 4.6. Your crazy

Thanks

 

Hahaha...yeah, must be...it wrapped it up around 11:30 that night and took off to the lake shortly after midnight. LOL!!! Good times.