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Discussion Starter #1 (Edited)
I searched and searched, but could not find a How-To on changing the spark plugs. I found some threads about tips, but no full how to.

So here goes...

Parts Required:
-Nissan #22401-5M015 Spark Plugs (x6, obviously) (AKA NGK PLFR5A-11)
-Nissan #14032-EA200 Upper Intake Gasket (x3, each gasket covers 2 intake ports)
-1 cold beer (or 2, or 3, etc)

Tools Required: ()=Optional, ie - you can do it without these
-10mm socket
-12mm socket
-Spark plug socket (16mm or 5/8 deep socket)
-12in extension
-short extension
-ratchet
-flat head screw driver
-needle nose pliers
(-blunt pliers)
(-Mini flat head screw driver)

To start, your engine bay probably looks something like this:


In my case, I have the K&N intake and found it easier to remove the air intake tube and get it out of the way. You may consider this.

First, remove the upper plastic shroud. Remove these two front bolts with a 10mm socket:


Then pull the plastic cover off. It is a little stiff, but it will pop off. I found it easiest to pry the passenger side up first, and rotate it towards the drivers side. There are two pop-off fasteners. One on each side. They look like this:




From here, the FSM says to drain the engine coolant in order to fully remove the throttle body. I chose to skip this since I wasn't prepared to refill my coolant at the time.

There are several hoses and electrical connections that need to be removed from the intake before we proceed to unbolt. I didn't do the best at taking photos of these, so I will do my best to recall them.

Disconnect these electrical connections:
  • Connector on Vacuum switch to canister on top
  • Grey connector behind intake near firewall
  • Throttle body connector
Next, use pliers to release and slide the vacuum hose clamps up the hose and disconnect these hoses:
  • Hose behind intake leading to brake booster
  • hose that goes up and over throttle body.
  • hose that routs around the back of the intake and joins the intake tube after throttle body
  • DO NOT remove the coolant hose from the bottom of the throttle body unless you have previously drained the engine coolant. Otherwise, just leave it there.
If your hoses are stuck even after releasing and sliding the clamp, try carefully using a small flathead screwdriver between the hose and the part it is mounted to. Alot of times, the seal just needs to be broken. I find these hoses come off best by pushing them off instead of pulling. Pulling will result in the hose tightening whereas pushing will expand the diameter.

There is an electrical harness branch connected to the back of the intake. It is mounted to a bracket that is bolted to the intake. I found it was easiest to just unbolt the bracket rather than trying to remove the plastic clips.

Next, remove the intake support bolts with a 12mm. It was easiest for me to use a 12mm ratcheting wrench. They are underneath and just behind the throttle body.

At this point, we are ready to remove the intake. Loosen the bolts and stud nuts reverse order of what is shown here:


Carefully extract the 5 bolts and 2 stud nuts.

Lift the intake up/slightly forward/slightly passenger. Watch for any missed hose and electrical connections on the way out.


Remember that there is still a coolant hose connected to the throttle body.

Find a safe location to set the intake out of the way to allow access to the passenger side spark coils. You may want to cover the intake ports to prevent foreign objects from falling down into the intake.

Next, remove the spark plug coils. There is one per cylinder. I failed to take a picture of this, but here is a schematic of what is in each cylinder:


I like to keep each coil with its cylinder. There are 2 ways to do this:
  • Remove one coil pack at a time, replace the spark plug, reinstall, and move to the next
  • or
  • label all coil packs, remove all, replace all spark plugs, reinstall all coil packs
I didnt want to switch between the ratchet and torque wrench a million times, so I labeled them and did all at once.

Disconnect the electrical connection at the coil pack then remove the bolt with a single 10mm socket. Pull the coil pack straight out of the spark plug bore and set aside.

Use a 16mm deep socket, 5/8 deep socket, or special spark plug socket (they have a magnet and rubber gasket in them to extract the spark plug with the socket) along with a 12in extension and remove the spark plug.

Take care to keep dirt and foreign objects out of the spark plug bore.

Prepare your new spark plugs with a small amount of anti seize on the threads and dielectric grease on the contact.

Install prepared spark plug and torque to 18 ft-lbs.

Install coil pack and press firmly until seated. Reinstall coil pack screw and torque to 62 in-lbs (~5 ft-lbs). Basically just snug.

Repeat until all 3 spark plugs are installed. Reinstall all 3 coil packs and connect 1 electrical connector per coil pack.

The FSM states that the intake plenum gaskets are non-reusable. However, I have seen plenty of internet engineers skip replacing these. I dont [email protected]#$ around, so I follow the FSM. Just replace them, you already have the intake off. Remove the 3 intake gaskets on the bottom face of the intake. I like to apply a thin layer of engine oil to the new gasket before installation. Install new gaskets.



Installation in the opposite order as removal. Refer to the above photo for the tightening order of the intake bolts. Torque all intake plenum bolts and stud nuts to 8 ft-lbs. I say again - Torque all intake plenum bolts and stud nuts to 8 ft-lbs. Over torquing these bolts can result in cracking your plastic intake.

Reconnect all remaining hoses and electrical connections.

You are now done replacing the passenger side spark plugs! Now you can move on to the drivers side. I bet you can figure those out now that you have done the passenger side.
 

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100k miles or so - I can't remember the exact number the manual says, but it's right around there.
I just looked at my 2011 Service Manual & Maintenance Guide: 'change plugs (NISMO 370Z) at 60K miles'.

60K seems kind of premature, no?

Thanks
 

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Some cars require spark plug changes sooner due to the way they spark. Many spark during the exhaust stroke as well. They do this mainly for emissions. But could also be looked at from a performance stand point. Kinda like a factory MSD.
 

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^^First gen #6 needed a contortionist!

While you have the throttle body off it is a good time to clean up the plates. Some of the carbon would not come off with TB cleaner. I used a small amount of gasket remover on the hard stuff but only on metal surfaces. Gasket remover is an aggressive solvent and will chew up any of your gaskets, paints or plastics it come in contact with. So use it very carefully.
 

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Discussion Starter #13
^^First gen #6 needed a contortionist!

While you have the throttle body off it is a good time to clean up the plates. Some of the carbon would not come off with TB cleaner. I used a small amount of gasket remover on the hard stuff but only on metal surfaces. Gasket remover is an aggressive solvent and will chew up any of your gaskets, paints or plastics it come in contact with. So use it very carefully.
I was going to clean the TB, but didn't have coolant on hand to re-fill my rad after draining to get the TB off. Ill get the TB cleaned on the next rad flush.
 

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Thanks for this. My 2010 OffRoad (precursor to the Pro4x introduced in 2011) doesn't have the upper plastic shroud (says V6 4L on it) from step 1. Just wondering if my model didn't come with it or some prior dealer maintenance missed reassembly during something.

Does it serve a purpose? I cannot imagine they would have included it on other models if it didn't do anything.

Thanks,
Rich
 

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They stopped using them on that year model I believe and no you don't need it many people remove them and keep them off.
 

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you guys are correct on the exhaust stroke thing. My Sentra with its qr25de and my buddies vq35de swap both leave the exhaust valve overlap with the intake stroke. which causes the intake stroke to get a little exhaust, this causes the plugs and intake plenium to get a little bit dirtier than they would in real life. you do need to change plugs on those motors more frequently.
 
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