There have been several topics in the R51 section over time asking about changing the plugs in the 4.0 V6.
See these topics...
http://thenissanpath.com/viewtopic.php? ... park+plugs
http://thenissanpath.com/viewtopic.php? ... park+plugs
http://thenissanpath.com/viewtopic.php? ... park+plugs

Didnt seem like anyone out there had done it yet because the plugs are good for at least a 100K.

Well, I just finished the task at 94,000 miles! My Nissan maintanance book says that plugs should be changed at 105K, but since I have two major road trips coming up, I figured I would do it now.

First of all, to clear up any mystery, this was NOT an easy job! Granted, the drivers side is a breeze. I did all three on the drivers side in about 20 minutes...
Passenger side was an entirely different beast! It took me about 2 1/2 hours to do the passenger side. Most of you probably know that the intake manifold is over the passenger side, and there lies the big problem. I am sure that a Nissan Technician knows all the tricks, has any special tools, etc. Heck, they may pull off the intake manifold to gain easier access to the passenger side. I just dont know.

As for the OEM plugs themselves... NGK PLFR5A 11. I always wondered if they were "Dealer only". I bought mine at Advance Auto Parts, I imagine Autozone will have them too. Advance part number is NGK 6240, and they retail for $9.99 each. They are the exact same plug as what I took out. I thought about using different plugs but these things looked great with 94,000 miles, so why mess with what obviously works?



My MVT (Most Valuable Tool) was about a 5 inch piece of fuel hose. Also notice the anti-seize compound which I applied to the threads of each new plug. Anti-seize is vital to threading anything into aluminum. I even use it on steel cylinder heads.



The chunk of fuel hose proved itself to be priceless for removing the old plugs once they were loose, and for installing the new ones with confidence of threading them in straight. The plugs sit deep inside the valve covers and are not visible while you try to thread them in. The rubber of the fuel hose provides a great sense of feel to thread the new plugs in and it is an extension that allows you to thread in by hand.

A 5/8 spark plug socket, a ratchet, and a 6 or 8 inch extension worked great for all three on the drivers side.
On the passenger side, it was alot of guess work and varied combinations of 3", 6", and 8" extensions, and a 3/8 swivel. The passenger side nightmare also is in getting out the coils. The rear two coils/ plugs are manageable with some patience. Number 1 coil, which is the front, was the most difficult due to the bend of the intake where the throttle body mounts to it. I ended up removing the throttle body to give myself a bit more access... it helped some.

I dont recommend this job to anyone. If you are an accomplished mechanic, and have confidence in your ability, then go for it. If all you have done is a tune-up on a lawn mower, you might want to pay a Tech to do it.

Good information. Thanks !!
I have had my share of nightmare plug changes in tight engine compartments so I feel your pain.. If you have ever changed plugs in a big block early Mustang you will know what I mean. One of my other cars is a 69 Mach 1 Mustang with a 428 Cobrajet and it is a real nightmare to get to those plugs.
I consider myself a good mechanic but I think when the time comes I will seriously consider having someone else do it.
I only have 30K now on my 05 so thank goodness I have a few more years before I have to worry about it.
Jim

I am probably gonna be doing the plug change soon as I am aproaching 85,000 miles. My biggest question to you is:
Did you not remove the intake manifold to change the passenger side plugs? if you did not then hats off to you man! I studied it hard and thought it would be almost impossible to change the passenger side without removing the intake manifold and since the shop manual states the IM must must be removed in order to replace the passenger side I figured that is the best way. Anyways share some more details, did you take any pics of the manner in wich you managed to remove them? specially the front most coil, how does it slide out when the IM is in the way?

twinblown wrote:...Did you not remove the intake manifold to change the passenger side plugs? if you did not then hats off to you man! I studied it hard and thought it would be almost impossible to change the passenger side without removing the intake manifold and since the shop manual states the IM must must be removed in order to replace the passenger side I figured that is the best way. Anyways share some more details, did you take any pics of the manner in wich you managed to remove them? specially the front most coil, how does it slide out when the IM is in the way?

Thank you! It is nice to get a "hat off" to my battle wounds.

I did not remove the manifold and I did get them all. I wondered what the service manual would say, but I didnt have a spare manifold gasket if I pulled off the intake.

Sorry, I didnt take any pics of how I did it. All I can say on the front coil is that removing the throttle body helped, and if the coil didnt seperate into two pieces, I would not have been able to get it out. I bet removing the manifold is much easier than my trial and error luck.

BMXPath wrote:

twinblown wrote:...Did you not remove the intake manifold to change the passenger side plugs? if you did not then hats off to you man! I studied it hard and thought it would be almost impossible to change the passenger side without removing the intake manifold and since the shop manual states the IM must must be removed in order to replace the passenger side I figured that is the best way. Anyways share some more details, did you take any pics of the manner in wich you managed to remove them? specially the front most coil, how does it slide out when the IM is in the way?

Thank you! It is nice to get a "hat off" to my battle wounds.

I did not remove the manifold and I did get them all. I wondered what the service manual would say, but I didnt have a spare manifold gasket if I pulled off the intake.

Sorry, I didnt take any pics of how I did it. All I can say on the front coil is that removing the throttle body helped, and if the coil didnt seperate into two pieces, I would not have been able to get it out. I bet removing the manifold is much easier than my trial and error luck.

The manual thats on the forum doesn't say to remove it.

great info. thanks for the pics and time.

I appreciate it

disallow wrote:

BMXPath wrote:

twinblown wrote:...Did you not remove the intake manifold to change the passenger side plugs? if you did not then hats off to you man! I studied it hard and thought it would be almost impossible to change the passenger side without removing the intake manifold and since the shop manual states the IM must must be removed in order to replace the passenger side I figured that is the best way. Anyways share some more details, did you take any pics of the manner in wich you managed to remove them? specially the front most coil, how does it slide out when the IM is in the way?

Thank you! It is nice to get a "hat off" to my battle wounds.

I did not remove the manifold and I did get them all. I wondered what the service manual would say, but I didnt have a spare manifold gasket if I pulled off the intake.

Sorry, I didnt take any pics of how I did it. All I can say on the front coil is that removing the throttle body helped, and if the coil didnt seperate into two pieces, I would not have been able to get it out. I bet removing the manifold is much easier than my trial and error luck.

The manual thats on the forum doesn't say to remove it.

Yes it does, in order to remove the ignition coil (obiously if you are going to remove the spark plug)
Page EM32

REMOVAL (RIGHT BANK)
1. Remove intake manifold collector with power tool. Refer to EM-18, "REMOVAL" .
2. Move aside harness, harness bracket, and hoses located above ignition coil.
3. Disconnect harness connector from ignition coil.
4. Remove ignition coil.
CAUTION:
Do not shock it.
INSTALLATION (RIGHT BANK)
Installation is in the reverse order of removal.

BMXPath wrote:

twinblown wrote:...Did you not remove the intake manifold to change the passenger side plugs? if you did not then hats off to you man! I studied it hard and thought it would be almost impossible to change the passenger side without removing the intake manifold and since the shop manual states the IM must must be removed in order to replace the passenger side I figured that is the best way. Anyways share some more details, did you take any pics of the manner in wich you managed to remove them? specially the front most coil, how does it slide out when the IM is in the way?

Thank you! It is nice to get a "hat off" to my battle wounds.

I did not remove the manifold and I did get them all. I wondered what the service manual would say, but I didnt have a spare manifold gasket if I pulled off the intake.

and if the coil didnt seperate into two pieces

How's that? twist and remove? A while back i had removed one of the coils on the driver side to look and the coil and long body seemed to be one piece. If it's a 2 piece that would explain how you were able to remove the passenger front most coil.

twinblown wrote: How's that? twist and remove? A while back i had removed one of the coils on the driver side to look and the coil and long body seemed to be one piece. If it's a 2 piece that would explain how you were able to remove the passenger front most coil.

Yes, the coil is at least two pieces. There is the hard plastic part that goes onto the plug, and then a rubber sleeve that connects to the coil. Note: I dont know if the rubber seperates from the top part of the coil. I wasnt sure about taking it apart, but I did it and it worked to get out number 1.
Btw, I did end up tearing a small part of the rubber boot trying to take apart the coil. It was in a small area where the rubber overlaps the hard plastic though, so it hasnt effected that coils fire.