OK guys so i bought this i35 a few months ago. I noticed a power loss, and bad gas mileage, slash power cut off when stepping into the throttle. So I figured it was time for a minor tune-up/ I dont drive the car everyday at the moment. So i bought a new air filter, and NGK platinum spark plugs. I was trying to decide if i should get the iridiums since they were only a $1 more, but i wanted to first see what was already in the car, so i went with the platinum plugs. I pull one plug out and its a champion brand spark plug!! and so were the other 3, Im like OMG! who would put these in this car? I only changed the front three because they were easy to do, havent taken the manifold off yet because of the drive-by wire system and i dont wanna mess anything up, if I dont know how to reset it lol. But would these plugs cause the problems i had? I immediately noticed a big difference in the way the car drives now after changing those 3 plugs, I can imagine how it would ride when i do the 3 in the back.

 

could be old plugs. Definitely swap them out since you have the new ones.

NGK platniums are great plugs. They are 100,000mile OEM equipment in the car so that says something about them.

 

If you want to save a buck or 2 or 3, get LFR5AIX-11. 6-8$ per and they're Ir, lasts a bit longer.

 

Probably almost 10 years ago I ordered NGKs for my 4th gen. The place sent me Champions. I called and they assured me that they were at least as good as the NGK. So I bought their line of BS and installed them.

What a fool I was. I think it was around 30K miles and the engine would start missing under hard acceleration. Thinking it couldn't be the plugs, I was trying all sorts of things. Finally I did replace the plugs and that was it.

Lesson learned.

 

lol i can agree man. Ive owned 4 nissans and ive never seen a champion brand spark plug in either one, so I was surprised to find them in this car, i cant wait to change the other 3 in the rear. It now feels like a 3.5 instead of a 3.0 lol.

 

Don't put the stupid brackets for the IM back on. Those things are worthless and hard to reach. It takes less than 5 mins to pull off the upper IM with those in the trash

You should be able to reuse the gasket with no issue. If you're paranoid, just smear a really thin layer of RTV on each side (I just use RTV by itself...or better yet, get the phenolic spacers, they're awesome). You might as well do the TB coolant bypass while you're there (less heat to the intake is always good).

 

do you know how many and what size bolts are on the rear of the manifold? Im only afraid of having to unplug the throttle position sensor on this car( drive-by-wire), and possibly having to go to the dealer to reset it and the idle speed. Do you have to perform the idle re-learn/ throttle position re-learn when removing the upper intake?

 

12mm, iirc, idk, maybe 4 bolts.

The TB stuff is a myth (or it would shot every time the battery went dead, none of it is logical). Those fools must have been sticking their fingers in the plate like a toddler. Regardless, the relearn can be done with the pedal dance or obd2 bluetooth adapter and your phone.

 

ok kool cause i saw a video on youtube, made it seem real easy to remove the manifold, and i wont be touching the throttle plate at all lol.

OK so the champion spark plugs that were installed from the previous owner were the 7975 brand, double platinum. Looks as if they are still fairly new, so i will keep them i guess, but still going to install the other 3 plugs tomarro.

ok so i got the intake manifold off, it wasnt as hard as i thought, alot more easier to remove than the one on the 4th gens lol. I didnt even have to unplug the tps. So I go to remove the three rear spark plugs, and they are NGKs, the fronts were champion lol. To my surprise The coil closest to the driver side is coated in oil, obviously not firing like it should if it didnt have any oil on it. So gonna have to order that 6 gen valve cover/gasket, replace the coil. But got it all back togather and it fired right up.

 

Hate that coil ... same happened to me.

 

Did the same recently. The 2 12mm bolts were never re installed. Then the one 10mm bolt that holds the bracket/harness for the rest coilpacks was not reinstalled either.

 

lol ive seen others post about finding oil in the spark plug tube, So i thought maybe i got lucky nope. looks like a design flaw.

yeah that mine easy to remove also because someone had already removed the 2 or 3 bolts in the rear, plus there is no egr valve on the 5.5