Just changed this belt on my 2006 V6 as it had an occasional squeal and 78k on the odo.
I know some others have asked for a DIY on this, so here's a quick write up post change.
1. Gather what you'll need:
- 10mm socket
- 3/8" ratchet driver
- flathead screwdriver
- Nissan serpentine belt
Here's a pic that highlights where you will need to unscrew/unbolt something:
2. Pop the hood, and remove the air intake plumbing.
- There are two 10mm bolts that hold the engine cover onto the engine and partially block the resonator box, which you will want to remove.
- Unbolt the cover and put the two bolts aside.
- pop the cover off so you can get to the two 10mm bolts with Phillips-head screw slots (use some muscle and it will pop off - it just needs to be out of the way, no need to take it completely off)
- unbolt/unscrew the two bolts that hold the resonator in place, put these two bolts aside.
- Now, use the flathead screwdriver to loosen the clamps at the intake and the airbox. I loosened both the clamps on the intake and the left-most one by the airbox.
- pull the intake plumbing off the intake and the airbox so its free, and move it off to the side. There is still a bypass hose attached, but it is flexible, so no need to mess with it.
3. Pull the old belt out.
- you should see where the 3/8 driver slots into the tensioner. Simply insert the driver and push down/counter clockwise to slacken the belt
- slide the belt off the tensioner, and once its clear, slowly let the tensioner come back up/clockwise until its fully extended
- pull the old belt off the pulleys, and take note how the belt needs to thread around/under the fan pulley, since you will need to reinstall the new belt this way and it can be a bit confusing
4. Install the new belt
- start by threading the belt on the bottom pulleys under the fan pulley, and work your way from right to left
- thread the belt so it is only off the tensioner and partially off the fan pulley
- re-insert the 3/8 driver and push the tensioner down/counter clockwise - be generous and make it easy on yourself
- slide the belt over the tensioner and slowly let off on the tensioner
- inspect the belt and make sure its seated properly in the grooves and centered over the fan and tensioner
- adjust the belt as needed by releasing tension to make an adjustment
- If you want, make sure the engine bay is clear, and start the engine for a couple seconds to ensure the belt is seated and moving properly. The engine will not run smoothly without the MAF registering air flow, so don't idle the engine or be concerned with a rough idle - you just want to get the belt moving and see that its fitted properly.
- If everything looks good, resinstall the intake plumbing
5. Reinstall the intake plumbing and engine cover
- pop the intake tubing back onto the intake and airbox
- bolt down the resonator with the two 10mm bolts
- tighten the clamps with the flathead screwdriver over the intake and airbox
- replace the engine cover and bolt it down with the two 10mm bolts
- Make sure the engine bay is clear, and close the hood - you're done!
Its an easy job, just be mindful of the cooling fan blades, they scraped up my right arm pretty good while I was trying to place the new belt.