FAQ: Underhood Insulation Pad/Liner

what does the liner do? it makes the engine compartment look nice! it might protect the paint job from radiant heat a little. but i think it just holds in engine heat longer. by removing it, might the engine dissipate heat better? what do you guys think?

i was thinking about this as well, i think that it would get rid of heat better but what would we do when it snows,then the engine is so cold

I'd think the main purpose is protecting the hood paint from engine comp heat.

in the days of muscle cars,they did not come,at least most of em, with liners. my legend ran 4 years without one,i took it off, with no prob to paint. and it was a great place for all my performance stickers from parts i bought. i ran my legend in queens,ny, not as cold as utica,but pretty cold,she allways started right up! and took no longer to warm up ,than with a liner. i think im going to take it off,give it a good cleaning and store it away for awhile. and keep an eye on the paint. here in vegas anything one can do to improve cooling is a plus! it gets so dang hot ! having a all white car helps too!

robotennis61 wrote:

in the days of muscle cars,they did not come,at least most of em, with liners.

I don't know about "most" of them, but the 60's and 70's Buicks all seem to have them and reproductions are available for most. Have new ones on my 68 GS350.

youre right! i dont think that it will affect the paint..so im taking it off im pretty sure it will help some....

I guess it doesn't make much sense to me. I think the "insulator" does just that, it keeps heat off the underside surface of the hood. So the heat that is rising from the engine moves off to the sides of the hood and escapes around the edges. Guess I don't see a drawback to having it in place. I really doubt that removing it will reduce temps. jmho of course.

ALTHOUGH, I doubt there would be any short term effects on the hood paint w/o the insulator. Long term "could" be a different story, so I'll leave mine on. It also likely serves a primary purpose of sound deadening, so that's a matter of personal preference.

Short answer: sound and heat.

Long answer. Differnt cars differ in the "need' for this. Chrysler had a problem with the 2.2 L turbo engines, well the turbos anyway, cooking off the paint. They responded by installing a flush louvered hood vent over teh turbo area and painting the hood with epoxy.

I suspect if there was a heat problem the thing to do would be add a vent or enlarge the grille. And if there was a heat problem the plastic engine cover would die first.

Albertj

They are considered a fire blanket. If you notice what is holding it on are several plastic pushpins. If a fire starts under the hood, they melt causing the liner to drop and (if all goes well) suffocate the fire. Molded to the aluminum hood is a plastic reinforcing "pan" that shields the outside paint from the heat.

ewolfe0050 wrote:

They are considered a fire blanket. If you notice what is holding it on are several plastic pushpins. If a fire starts under the hood, they melt causing the liner to drop and (if all goes well) suffocate the fire. Molded to the aluminum hood is a plastic reinforcing "pan" that shields the outside paint from the heat.

I know I've seen a pic of a Riv with the hood melted off from an engine fire . . .

I don't see how that could possibly work, a fire could draw plenty of air up from the bottom.

I'm thinking of removing the rear plastic pins at least, I'm sure that's what's pressing against the STB and causing the hood to bow up.

call me crazy but after my sweet looking engine swap im taking my liner off and im going to put some mirrors in place. just for added show look

Nobody ever said it was a good design but that's what it's there for. I have run the Riv without it for a while yet and have not had a problem. If you want to keep the engine bay a little cooler, remove the top seal from the firewall to the hood.

ewolfe0050 wrote:

They are considered a fire blanket. If you notice what is holding it on are several plastic pushpins. If a fire starts under the hood, they melt causing the liner to drop and (if all goes well) suffocate the fire. Molded to the aluminum hood is a plastic reinforcing "pan" that shields the outside paint from the heat.

I'll have to disagree here Eric, the "pan" is also aluminum. Riveted to the hood, and then the liner is attached with plastic pins.
The corrosion I have on mine is a good indicator of that!

I could swear mine was plastic but I guess I can't tell because of the paint over it. I guess I'll find out soon enough when I cut it for IC install (if needed)! I've been know to be wrong on several occasions though! lots and lots of occasions...

what if i took off the liner and applied stick on heat barrier? its a whole lot thinner than the stock piece,and i can cut it to fit the ,between, reinforcing ribs of the hood. i might even look cool! and at the same time im keeping the heat from potential heat damage. whada ya think?........

I like that idea.

It'd probably reduce weight too! As long as you replace the hood liner with something that serves the same purpose, the technology is 13 years newer so it may as well be thinner.

right! im gonna do it. next pay day!

I want to see how yours turns out, if it looks good I'll put it on my list. I'm sick of looking at the huge hood gap the STB causes.

ok. coming soon!

I took Mine off it was all nasty

Hey robotennis, I'm interested in if you took the insulator off or not, or if anybody else has and has had any problems w/paint or the like.

I'm either going to clean mine or remove it. Sorry to revive an old topic, but I'm interested in doing this.

I removed mine last fall, no problems so far. The raw metal under hood isn't so bad to look at.

I think it's there more for noise than for heat.

I think you might miss it on a long highway trip.

Albertj