nice write up

i wish i saw this earlier than trying to figure it out myself

 

cool thanks............

 

Just replaced my spark plugs today, thanks to your write up. Excellent job w/ the pics and arrows (helped a TON)! Went ahead and changed the PCV valve, cleaned my battery terminals, cleaned and oiled the K&N and Seafoamed.
Thanks again,
rob g.

 

Never heard of seafoamed, what is it?

 

Changed mine to the Op's IRIDIUM IX LFR5AIX-11, and the car started idling rough after a week, and the SES light went on - turned out to be code p0300.

My mechanic says that getting OEM plugs should clear it right up, runs normal except for idle....I guess I'll find out tomorrow when I pick up a set. I did drop one of them on the hood of the car, about a 1 foot drop, but it didnt look any different than the others. I'll post results with the OEM's tomorrow.

 

Sounds like your mechanic is trying to earn himself some business. Don't give it to him!

Honestly, it sounds like one of two things.

1.) Plug is damaged.

2.) Coilpack isn't installed properly.

I would take all of the plugs out and inspect them. Changing to iridiums shouldn't cause that problem unless the electrode was cracked and split after a week of being run in. A hairline fracture + heat + pressure = failed part.

Checking them only takes an hour and it'll save you money.

 

On YouTube search for Sea Foam. You will find some informative videos on it. You may also find it on this forum, just do a search. Sea foam is to get rid of the carbon build up in the internals of the car.

 

I changed my plugs this past weekend using this DIY and the DIY Video Series vids.

Please update the TOOLS REQUIRED portion to list both a Inch-Lb. & Ft-Lb. Torque Wrench.

^^While the directions do clearly state Inch-Lb. or Ft-Lb, I first read the tools required,thumbed through and saw the Ft-Lb torque wrench and went with that.


Ultimately, the issues was my plugs needing to be gapped( NGK Laser Platinum, all were Gapped at .039! ), and the little valve on top of the upper plenum had it's little rubber cap knocked off and lost.
There is now a piece of rubber hose on there with a small nail stuck through the hose and wrapped with electrical tape.

I need to find somewhere to purchase a new one of those. That rusty nail doesn't match my polished plenum, lol.

 

About to jump into this read a ses code earlier where my #5 cyl left me. Does anyone know the cylinder order on these engines? I got ngk laser platinums, im very excited to toss em in. Ill post back when im done.

 

Well all is done, I had a misfire on cyl 5, and finished the plug replacement and the problem got worse,I found oil in a few plug holes so I am off to the infiniti dealer tomorrow. Great writeup though it made it quite a quick process! Thanks!

 

If you know it's on #5, then it could very well be just a bad coilpack. The coilpacks are available at Advance, O'Reilley's, or even AutoZone, and they're about $70-$75 apiece. Go buy a coilpack and replace it on #5 and see if it fixes the problem. If it doesn't, then just take it back to the store. #5 is the cylinder on the passenger side closest to the back. I'd give 99% this will fix your problem.

 

ive noticed oil in a couple or more of the spark plug cylinders on mine. when this happens, you need the o rings changed on the valve cover itself and possibly a new valve cover gasket. its very typical with the vg engines.

 

Great theory, but the problem is that the G35/350Z valve covers have spark plug tube seals that are non-replaceable. You have to change the whole valve cover in order to change the o-rings.

 

I'm planning to change plugs on my 04 sedan. I have Stillen intake and cat back exhaust. Should I upgrade to one of those high end $10 plugs or stick with stoke NGK. Is there really a noticeable performance increase over stock type plugs.

 

Eih, could go either way. I think a lot of the difference people see is just from NEW plugs, not upgraded.

That being said, both times I changed mine I went with the pricey set.