Ok so I have a new 4runner Trd and I have hood flutter that drives me crazy. The dealership took a look at it and said hmmm well not sure what to say. WTF?? OKay so any way is it me or does anyone with a hood scoop hood notice it? It's up towards the windshield and it's just sits and flutters even at High speeds on the freeway. And adjusting the little rubber stops at the front (under the hood) makes no difference. So my question . Is that normal? Seems very untoyota like, my landcruisers hood doesn't look like its ready to fly away. Any help or comments?

Yes, it's normal. The hood is not structural in any way, just there to cover the engine, so they made it as light as possible.

There are 2 things (that I know of) you can do to "fix" it, which I have done. 1 is to put sound deadening material on the underside, which increases its weight and changes its resonant frequency. The other is to cover it with vinyl wrap, which also gets rid of the annoying glare, if you get a matte finish.

Yes mine does it too. I believe that the front bumper radiator area opening is so big and flat on the front of the truck that when driving at high speeds the large amounts of wind forced into the engine bay find the path of least resistance and flood the upper part of the hood area which in turn the tries to find an exit flow area, which would be cowl area that doesn't have an equal exit flow to the intake of air, causing the thin ass flexible aluminum hood to waddle back and forth like it's got Parkinson's... At least that's my take on it.

My magnet says it's thin ass sheet metal.

FWIW - My SR5 hood (no scoop) also undulates somewhat uncomfortably at freeway speeds - but you get used to it. I don't see how the paint can take all the flexing w/o eventually cracking/flaking, but I guess it's relatively minor stress in the end.

No sound deadening material make a difference. A local guy with a TE have put some under it and told me it helped a lot on the fluttering. Also made the interior quieter, but not that much...

Its a TRD Pro hood which has been shaved to racing depth to encourage high speed maneuvering! I understand the fluttering also reduces chances of whistling by disrupting the airflow over the hood.

(The above statement has NOT been certified or endorsed by any professional employee of TRD, Toyota, or 1engineer's professional background)

Hmmm......... I've never noticed that, maybe it was because I was feeling too BADASS with my hood scoop

2010 Trail with scoop. I used expanding foam in the reinforcing under the hood. Use masking tape on the edges and holes and shot the foam into the channel. Gotta be careful and not put too much. The sucker really expands and can bow the hood if you put too much. Let it dry and trimmed off the excess. Almost no flex and not so irritating in bright sunlight. Adding some Dynamat type sound deadener would probably eliminate the rest of the vibration.

Am I missing something here? Is there no way to secure the scoop with 3M automotive trim grade double sided tape? As long as you have a lip on the hood on which the scoop sits it will do the job very nicely. Remove the "scoop" (because lets face it, its a non-functional piece of jewelry), apply the tape to the lip, press said scoop into tape and tighten it down. It'll be rock solid.

Disclaimer:
I have no clue how the scoop mounts and I'm just assuming its similar to the way Subaru mounts theirs on my WRX and my wife's Forester XT.

Other than the plastic insert in the front the scoop on the Trail is part of the stamped steel hood. The OP is referring to the fact that the hood moves around a fair bit over bumps or when hit by, say the wind gust from a semi going the other direction at highway speed. It's the same problem with all 3 models of the 5th Gen. Not just the ones with scoops.

Whoops, confused it with my BRZ.

Hence the disclaimer.Thanks for enlightening me.

For what its worth the hood on my SR5 moves around a fair bit at highway speeds as well.

For what it is worth, the hood scoop is sort of a carry-over these days, though it was functional at more than one point in the 4Runner's history; just not for the US.

The 4th gens came with a 3.0L 1KD-FTV Diesel option and the scoop funneled air to the intercooler set-up. But they left it untouched for the Sport Edition Trim on the US 4th Gens, despite not carrying the diesel over to the US. I think at this point they just kept it mainly for looks on the 5th Gen, unless they plan on a diesel sometime in the future (doubtful.) Ironically, you'd think the Tacoma would have shared that option as well, but the Tacoma is really only a North American vehicle; the Hilux platform does the diesel duty overseas (yet they retained the hoodscoop the same as the 4th & 5th gens.)

This afternoon, I drove mine to an undisclosed MPH (the speed I was going some things on my body was fluttering...scaring self) to see if mine would flutter because I had never noticed any movement described at all.
***It was rock solid to my amazement.***
Could the solution be checking all of the rubber bumps to make sure they are making good contact?