For anyone who interested in changing their spark plugs on their own but not feeling very comfortable, this should help. I have a 2007 M35x so, at the least, this would be the same for the 2006 M35. I haven’t seen the V8 or the 08/09 car so I can’t say if this process is any different. This should give you the general idea though.
Task: Change The Spark Plugs
Time: Took me 2 hrs
- Socket wrench
- 14mm deep socket for the spark plugs (I’m not exactly sure of this size because I forgot to make note of it – I’m pretty sure it’s 14mm)
- 10mm socket + varying length extensions for all the bolts/nuts you have to take off
- 6 spark plugs of your choice (I used 6 NGK V-Power copper plugs). Nissan motors work best on NGK plugs.
- Spark plug gapping tool. Napa sells them for like a dollar. The plugs should be pre-gapped to .044″ but I like to double check.
- Flat head screw driver
- An extendable magnet (this helps greatly in getting some of the bolts out without dropping them below the motor)
1. Open the hood and remove the plastic covers to give yourself some space. The engine cover is held on by 4 10mm bolts/nuts. The other two just pop off with clips.
2. Disconnect part of the air intake that goes into the throttle body and move it to the side (I wire tied it to a hole near the fender).
Should look like this when you’re done with the first two steps:
3. Loosen the engine harness by taking off the following two 10mm bolts. This will give it some slack so you can pull the coil packs out.
4. Disconnect the PCV Hose to again offer a little more space to get the coil packs out.
5. Unscrew this bracket (not sure what sensor this is) to allow you to remove the middle coil pack on the passenger side of the car.
6. Remove the two 10mm bolts holding this sensor/bracket on the driver side part of the engine:
7. Now what you’re left with is 6 coil packs and spark plugs. Each coil pack has 1 10mm bolt holding it to the block. I only have a picture of two of them, but you should be able to figure this part out. Be careful unclipping the harnesses.
8. Once you remove the coil packs, you should be left with just the plug.
9. I believe the spark plug is 14mm deep socket, but I forgot to note this so I’m not exactly sure. Be careful unscrewing/screwing it in and the rest is reverse of removal.