Hoodliner for Ticking is a FAIL

SAVE YOUR MONEY. (sorry, this got long)

I bought a hoodliner claiming to absorb sound as well as provide thermal protection for the hood paint.

Using an iphone app, I took A weighted frequency spectrum measurements (10 seconds), before and after, in the access cab outdoors (no reflections) with windows rolled up, stopped and idling. The iphone was held horizontally with the microphone pointed at the windshield near the driver's head position.

Attached are the results. Absolute numbers are not important. Relative before and after is what I was after. I checked the app calibration and it is reasonably close to an SPL meter I have but this is far from professional equipment. Take absolute numbers with a grain of salt.

When comparing before and after, ignore everything except the blue "AVG" and "MAX" dBA numbers and the red max frequency band hold bars. Everything else is instantaneous and not relevant.

The ticking seems to be in the 1.25KHz frequency band. I checked with a stéthoscope and I believe it is the high pressure fuel pump making the noise on the passenger side of the engine, though minor injector ticking can be heard all over the engine.

A 3dB difference is just barely perceptible by a human. This is a total failure ticking noise wise. I think the cab might be a bit quieter in the lower frequencies but that makes the ticking all the more noticeable. I think the ticking is really coming from the outside thru the doors. Some soundproofing of all surfaces might actually shield you from the ticking. Too much trouble for me.

BTW: the box it came in showed expected before and after chart and 3dB was mostly what it showed. That is a joke. If these people are competent acoustical engineers, the product is a fraud.

And there is a click bait youtube guy that claims it made the ticking go away with this "secret" fix. Another commenter called him out as a jackass and I guess I now agree, though it was only one of the inputs to my decision to gamble $55 to nail the ticking.
I'm not posting a link to his video to give him more of what he wants (clicks).

I did spend a fair amount of time trimming the liner to meet the gaskets, etc. The little that was leftover I applied to the firewall..not sure it made any difference. The firewall already has some factory material on it but it was not completely covered in the upper portion. There is a thread where a guy covered it with sound deadening material and claims improvement, but he showed no numbers and it was for a 2nd gen. For the 3rd gen I think this will not work.

So, bottom line: I think the cab is a smidgen quieter but now I notice the ticking all the more. The thermal protection of the hood paint from the engine is probably BS. Would I do it again...NO.

The product was

$79 Dynamat 11905 Hoodliner 32" x 54" x 3/4" Thick Self-Adhesive Sound Deadener

Dynamat 11905 hoodliner. $55 shipped on Ebay.
Attached pics of installed hoodliner, before and after dBA measurements. Practically no meaningful difference in those screenshots. Disappointing but not surprising.

Installed:


Before:


After:

 

The hood liner looks like the roll of silver diy insulation I can buy at Home Depot but thicker.

 

could help with the hood vibrations.

 

what i got was 32x54...bigger than what you show (SEE EDIT). the foam is claimed to be sound absorbing which i bet would not stand up to scrutiny.
I was an acoustical mechanical engineer eons ago. I dealt mainly with environmental highway and railway noise. I suspected and should have known better
than to hope to be lucky. I think bottom line, lining the hood is a waste of time if you are after quieting the ticking, possibly unless you insulate the doors and floors etc.
Doing just the hood is a waste of time regardless of youtuber recommendations and product claims, at least for our trucks.

EDIT: oops: I misread the ad. it is 23FT...not inches. It looks like bubble wrap with a cover but not sure. probably just as effective

 

I think most of the engine noise is not coming from the hood, through the windshield, and into the cabin. Its going to come through the firewall.

Add sound deadening to the firewall and you will get a better result.

Reading the reviews on Amazon shows most people are putting this stuff on the engine cover inside motorhomes.... where the engine is right there under your feet. They are saying it makes a huge change and even provide db numbers.

 

I take it none of you have ever ridden in a vehicle from pre 90's? Everything shy of a caddy was a noise box.

Either I'm def, or ya'll have some crazy micro hearing that get bothered by any sound that a Tacoma makes.

Just wear ear muffs!!

 

lol. my high end hearing is f...ed and i still hear too much. i can't imagine what a person with good hearing hears.
PNW not so wet now is it? oregon here too.

 

Maybe. I thnk even the firewall is a waste of time unless you do the other surfaces. open the door and you hear the ticking much louder...so some
significant portion is coming thru the doors i think. we agree hood is a fail.

 

Was going to say “it’s a truck” but maybe instead just another reason to go electric instead. But really, it’s a truck, nothing short of gutting and starting from scratch will eliminate all noise pathways. I put noico under the roof and rain noise is muted but road noise is still just as loud and comes through the glass.

 

Amazing how people think their $40,000 truck is a $200,000 limo. Dude.........seriously.........

 

yeah, its a truck and fine with me. if a simple fix, like some claimed this would work, made a difference then great. not to be. no big deal except i am so over the fools posting their secret
fixes with no understanding. as far as road noise, i think you might want to look at the rear firewall. i think there are vents back there and lots of road noise coming in there. could
be wrong.

 

you misunderstood. i tried something and wanted to let people know it does not work. it is still a truck. not trading it in investigating it was actually fun. would have been better if it had worked.

EDIT: and trying to compensate for some of the misinformed bullshit out there (not you) is a noble cause!

 

I dont know why anyone would even think this would work. Sound doesnt just travel up. It travels in all directions. So you would need to completely enclose the entire engine bay top to bottom with this stuff.

 

I like music. Loud music.

 

So I have done a partial install of Dynamat's hoodliner on my truck. But I haven't done it for sound deadening, but to prevent heat from getting absorbed into the hood.

From inside the cab, there is little audible difference.

 

Yes, it’s an AC so it has the vent. I’ve done noico on that wall too and might try some open cell foam in/over the vent but a lot of noise seems to come right through the rear glass. It’s nice to make it a little better even if it’s still not a high end vehicle.

 

what else do you guys in Beaverton do?

 

Exactly. I doubt the open cell foam will do anything for the vents. The foam is not likely to absorb any sound and it is still an open air pathway. For damping pathways (like intake or exhaust)
it usually requires a significant contraption with soft absorbant material or a resonating chamber (think muffler). My guess is the noise thru the rear window is actually thru non-airtight seals.
And maybe some thru the thin glass. Not much you can do about that easily either.
BTW: the claim on the hoodliner is that the foam is a combo of open and closed cell. I dunno...nothing beats heavy material. This stuff is very light.

 

Totally right. I just wanted to give it a shot since it was cheap and others claimed it worked, including Dynmat but they hedge a little there. They know. So now i have a
shiny heat shield that I really didn't need. not so bad. Had to call it out for what it is and isn't, though, to save someone else the bother.

EDIT: as far as it having the possibility of working...if the hoodliner actually had meaningful sound absorption properties, it could provide some relief from reflections off the hood and transmission thru the hood. That is apparently not the case and the hood itself is not that important to cab noise.
I think for ticking it is useless (counter to idiot claims I have seen) but I think it actually reduced some fan noise but very minimally.