what type of performance increase am I expecting to go with NGK Iridium sparkplugs? What is the OEM sparkplug tip made of? platinum?

I want to follow through with this DIY but I'm curious to know what kind of benefit I'll be getting from doing it.

Thanks!!

 

Akoustic, it is my understanding that the OEM plugs are also Iridium. It is my understanding that Iridium plugs are the best. I have been pleased with other NKG plugs I have purchased and am sure they make an excellent Iridium plug also. The performance improvement would equate to bringing your spark back to its original performance, possibly a more complete burn, gaining some power improvement and could also result in a modest fuel economy improvement.
Good luck

 

The original plugs are NGK-R, platinum plugs. I think iridium plugs are a good thing for boosted or sprayed motors, because they stand up to heat a little better without breaking down. But for a naturally aspirated engine, I think the platinums are good enough that you'll never tell the difference. The platinums are as little as $3 apiece, and the iridiums are at least $7 apiece - more likely up to $12 or $13. I used ND platinums when I did my stock-engine plugs, and they're working fine. This is an area where you can easily spend a lot of money on hype, for not much, if any real gain.

 

Thanks for this DIY! I was putting in my MD 5/16 copper spacer and while researching the DIY on that saw where someone suggested replacing spark plugs while I had the plenum off. My '05 coupe has 65k on it so I figured it would be a good idea and was it ever! It made the spark plug change amazingly easy. Also cleaned my TB and MAF sensor since I had things tore apart anyway. Everything went pretty smooth, it took me and a friend about 3-1/2 hours from start to finish working at a leisure pace. The car fired right up on the first try with no strange idling or lights coming on. Took it for a drive and again, no issues. Had to let my buddy drive (I consumed a few beers while working) so it was hard to really gauge any differences from the passenger seat. I will be getting it out tonight to romp on it, though!!!

Just wanted to say thanks to all in the community for the advice you give. I'm no mechanic, but I can turn a bolt and follow directions and ya'll make it much easier.

 

hey man QUADCAM you still out there I having the same problem as nyqueenz

 

I know this write-up is a few years old but, Excellent write-up!! Got my plugs changed in 45min!!

 

what if you over torque your spark plugs? I noticed after the change my wrench was set on 40ft lbs and I swear I had it on 20 when I installed the plugs. I really do not want to go back and back them off and re-torque them. I highly doubt I will ever change plugs on this car again....

 

Personally I wouldn't touch them unless you start experiencing a problem. A problem might should up as a miss. The reason they specify a torque is so that the threads aren't ripped out of the aluminum head and so that the plug gets seated in the head properly. THe good news is that on your head, there is plenty of thread mating surface which means it is more difficult to strip the threads.On old chevy heads there is so little thread surface that its even easy to strip the threads on iron heads that they make inserts that can be used to repair stripped spark plug threads.

Unless you felt the plug "give" (that is get looser or fail to get tighter as you expect) as you tightened it, you probably haven't stripped it. Hope you used the OEM plugs or equivalent so you can get another 100k miles out of them!

Brian

 

Awesome! Thanks for the input Brian. I was a little worried about it, but feel much better now. I installed a skunk2 spacer at the same time, now all I have to do is figure out the whistle noise..

 

Been there done that. One time I was bolting on an oil pan which had bigger bolts at the corners and smaller bolts along the sides. I looked up the torque for the bolts and after snapping off two bolts I figured out I had looked up the torque for the bigger bolts. Bad feeling when you keep wrenching and the bolt stops getting harder to turn and then just goes.....

 

Just used this DIY. Very helpful! Thaks worked very good

 

I changed my spark plugs and found some oil,

 

Thanks for this write up! I'm going to tackle this soon and the pics are going to be a great tool!

 

I switched to NGK iridium plugs but thinking of going with one step colder plugs since I will be going FI in the near future. Good DIY tho

 

My husband just changed plugs on our 2004 (new to us) G35. Rough idling, so he thought he cracked the coil. BUT, it looks just fine. Said he also heard a crack like sound, but can't see anything. What might have gone wrong for a first-time inifinity owner not used to the cramped space (and darkness!) in this engine?