I finally got around to doing this. It's not as dramatic a change as the front and rear fenders (the worst offenders), but it's very noticeable. Pretty much killed all of the accessory drive noise (a/c compressor, etc.) and a lot of front end road noise, and mutes the engine a little bit. Definitely quieter overall.

Several ways to do this, but this time I wanted to copy something I'd seen before and use the stock plastic clips to hold a better hood liner in place. I used products from Second Skin, some aluminum tape and ten replacement hood clips from Nissan.

Started with damping using Damplifier from Second Skin:



I needed to leave the holes for the clips unobstructed and I didn't want to add more weight than I needed to, so I kind of quilted it in like this. Except for doors where I want them to be super-deadened for sound quality, I generally add just enough to damp away resonance in the panel. It doesn't take that much, particularly if you put it on the center of mass of the unbound panel area...which is usually just the center. Since this ends up getting covered I don't care that it looks all over the place either.

Next I used some left over scraps of "Motor Mat" to fill in the depressions between the ribs:



Second Skin doesn't sell this product anymore but Dynamat still makes one called Hoodliner I think. Before I've stuck a sheet of this across the hood and called it a day. It's a really good open celled foam with an aluminum barrier that absorbs high frequency sound well.

Last I used a sheet of Heat Wave Pro, which is something like fire retardant carpet jute with aluminum barriers on both sides:





I started by using the stock hood liner as a pattern for both the rough outline as well as the holes. I did final trimming in place and used aluminum tape to seal the edges to prevent water intrusion.

Looks a little better in person, and it works a little better than I expected. Particularly for that annoying A/C compressor noise I don't hear much of anymore

Nice job, have been thinking about increasing the sound dampening materials through out my PF. The hood looks like a good place to start.

Looks really good!

When are you going to clean your engine? (somebody had to ask)

I know you just completed this mod, but does this help stop the bouncing hood?

NVSteve wrote:Looks really good!

When are you going to clean your engine? (somebody had to ask)

Ha! Yeah, I nearly stayed up even later to wipe things down a bit. The flash made the dirt stand a little prouder than it really is though

volvite wrote:I know you just completed this mod, but does this help stop the bouncing hood?

I seem to remember some posts here about that but I've never had issues with my hood flapping/bouncing/noticeably moving. It vibrates a bit like any hood, aka "cowl shake," and this does make that go away.

I've had hood problems with a previous Nissan, so I pre-emptively changed the three rubber bump stops for the hood (and the four or so for the hatch) a couple years ago. Even when you can still adjust them out to level the hood leading edge I think they just get too dried out and hard and don't function properly after a while.

My previous vehicle had a tiny bit of movement, just enough to where the hood latch would vibrate annoyingly in sync with vibration from the engine. Had to change them a couple times over the eight years I owned that car. As a matter of fact, when people are complaining about the chirping hood latch on their Pathfinders here, I wonder if it's chirping because there's excess movement to begin with.

Anyway, dunno if that's the same thing, but for now my hood doesn't bounce

looks so great, good job

Looks like an effective way to eliminate noise. Thanks for sharing.