I've never replaced spark plugs or coil packs on a car before, but I figure it's time to man up and make it happen on my Q!

Got the car recently, cant find any recent records or any plug changes. Even though car seems to run smooth and I'm not getting any codes I figured it was time, and might as well replace the packs while I'm down there too. Just want to make sure I dont screw anything up and would appreciate any advice. I've already looked at several videos and other forum posts on this, just want to get a better idea before I start.

THINGS I'M PLANNING ON BUYING
-NGK 7090 Platinum plugs from AutoZone
-Coil packs from AM After Market Auto Parts, seem to be a good deal at $120 for all 8 and have 10 year warranty (http://www.am-autoparts.com/Infiniti/Q4 ... hgod7YYPsw)
-A bit of anti seize for the threads
-Some sort of electrical fluid for inside the coil packs where they connect to the top of the spark plug (recommendations?)

QUESTIONS I HAVE
1. Do I need to gap the plugs?
2. Are there rubber gaskets below the plugs, or are the plugs just sitting on the block?
3. How much torque on my torque wrench is needed to seat the plugs?
4. Any useful tips/tricks from you that you've found?

Thanks!

do the pass side first, easier. slide the trim cover out without removing/disturbing the fuel hoses unless you plan to change those anyway (shouldn't need to though).
drivers side you need to remove the snorkel and a few connectors.
didn't look up your NGK number, but use the factory recco'd pfr5g-11 plugs (double platinum).
no gapping
no rubber, they will come with an integral crush washer.
14-15 lb-ft
I use a drop (no more) of permatex anti-seize

will be interested to see how your knockoff coils hold up.

prolly obvious, but take all 16 coil hold down screws out and get them away before removing plugs. they are sized to fall into the cylinders....

Hi 3Q Jay,

Did you make a few YouTube videos that documented a spark plug change on a dark-colored Q45? If so, that's where I got the NGK 7090 Platinum plugs recommendation from. Have you changed your mind since then if that's the case? The NGK PRF5g-11 plugs are double platinum and cost quite a bit more, is there a major difference?

And is it overkill to put a drop of dielectrical grease between the top of the spark plug and the coil pack?

Thanks again.

3Q Jay,

Just realized that video was totally someone else. Video I was referring to was here- https://youtu.be/FIp__fBP0Uw

Definitely get the OEM specified plugs. I haven't heard of it on this series of Q, but on the older ones, aftermarket Bosch plugs had a bad habit of dropping electrodes into the cylinder I have had good luck getting them from Advance Auto Parts with a coupon code. I would also stick with OEM coil packs. The last time I checked Rock Auto sells Hitachi packs, which is the OEM supplier to Nissan.

I use dielectric grease lie you describe... probably a little more than a drop. By the way, if you find an oil around the spark plug, you'll want to abort the mission until you replace the valve cover gasket.

Heath

MovieMaestro10 wrote:3Q Jay,

Just realized that video was totally someone else. Video I was referring to was here- https://youtu.be/FIp__fBP0Uw

That was me, on my old '98 t.

It's not hard to do them, but dedicate at least half a day to it. The biggest worry was that the plugs were going to bring the threads out with them, because they were TIGHT. I actually delayed doing the plugs for that reason and ended up killing a couple coilpacks.

I just used the standard NGK platinum plugs from Autozone, the cheapest ones. it ran fine with those. That's exactly what the book called for and I wasn't about to spend a lot of money on plugs just it's an Infiniti.

It's a Nissan, is what it is, and an old one at that. I also got a couple used OEM coilpacks from the junkyard, which worked fine.

Main thing is to MAKE SURE YOU DON'T CROSSTHREAD THE PLUGS GOING BACK IN. Do that and your day, week and month is screwed. Use wobble extensions because space is at a premium toward the firewall end. Good luck.

TylerW, thanks for making those vids! Already used your cabin air filter replacement video as a guide and it was really useful. I'm def planning on a half day with no hurry as it's my first time.

My biggest concern is what you mentioned- Breaking off the head of the spark plug. Was thinking of bringing some spare throttle body cleaner and giving it a bit of a spray down there and waiting if they seem to be stuck. Here's hoping last owner used some anti-seize.

Any tips to make sure I dont crossthread the plugs going back in? Just take my time? Guessing I wont be able to screw them in by hand to start. I have a few different wobble extensions that I bought just for this job to help with the tight places.


Heath/Q451990- When you say look out for oil around the spark plug, do you mean on the top (like it dribbled down past the coil pack) or inside the cylinder?

Oil on the plugs - you'll know it if you find it... A giant sucking sound when you pull the coil pack off is usually the first clue. But it'll be oily on the outside of the plug. Once you unscrew the plug, it'll run down the threads and into the cylinder. I haven't ever heard of plugs seizing in the head on a Q, or any Nissan product for that matter - but it happened to my dad on a Mazda in the '80s, so I always use anti-seize on my plugs. As long as you're using a spark plug socket (it's like a normal deep well socket with a rubber insert that holds the plug in place, you should be able to start and hand tighten them using it in combination with an extension. Starting them by hand makes it very unlikely you'll cross-thread anything. I think this job will be easier than you think.

Going with NGK plantinum plugs from Autozone...Any one know if they need gapped, or what the manufacturer recommends?

Autozone computer said .044, in which case they would need gapped. I'm guessing I need a special tool for that...The gap measurement "Coin" will mash the end, right?

NGK are pregapped no? its says it on the box

They're NGK 7090's (BKR5EGP). I do see a little symbol with a big red X on it, that shows a screwdriver head bending back the gap pressing against the contact point...I thought that was saying, "don't gap the plug like this". Does it mean don't gap at all?

is that the OEM plug? I always thought the Q45's were running the Pfr5g-11's up to the Pfr7g-11's, and I'm pretty sure NGK is pre gapped.

you don't stick anything in the gap of an iridium or platinum plug so as to not disturb the plating.
coin/feeler gauge gapping a standard copper/copper plug is fine.
the logic for using the double platinum is that they last 60k or more miles.
copper will wear out much faster. so will the copper grounding electrode on the iridium center conductor plugs.
everything has a reason. once you have all the data then your decision is just that---a decision. hopefully an informed decision.

Stuck with the NGK 7090's platinums, and according to both Autozone and Pepboys the correct gapping is .044

Got one of those round gapping tools, not the coins, was like 3 bucks, just have to pull the 7090's out just a bit.