Worth replacing? Mine is falling down in places. It seems each time I close the hood one of the push in fasteners that holds it up breaks and I find it laying under the car or someplace in the engine bay.

I understand that it's used to keep the heat from discoloring the hood paint, reducing noise, possibly suppress engine fire. How many of you have yours still?

I could just replace the fasteners I suppose, though the insulation itself is pretty ugly. I took it off my Toyota about 7+ years ago when it started falling, with no effect to the paint.

 

I think it's less of a fire-prevention and protect-the-hood-from-heat issue as it is a noise issue. If you don't mind the additional noise coming from the engine compartment during normal operation, don't replace it.

 

I never thought they really could do much as far as fire suppression. Might give someone some peace of mind, but I figured for the clips to melt and that thing to come down and smother a fire, it'd be pretty toasty in there already.

As for the noise, it's never bothered me...

 

Got some Knuaf air duct liner insulation from an HVAC sheetmetal ductwork shop for mine. Nice stuff, as has a reinforced surface on it. Used the old liner as a cut out template, and ordered the plastic clips from Napa. If you have such a shop near by, surely they'll sell you some material.

 

I still have mine. Replaced it 26 years ago. Wanna see how it looks now? (can you say - like new)

My opinion? If the car didn't need it Olds wouldn't have put it there. Replacement plastic fasteners are cheap. Once you pull the originals out, the ridges on the plastic won't hold worth crap and are prone to falling out just like what you're experiencing. If you take your car to shows (and I imagine you do) you want to present the best image of 74 you can right? How much is a new liner?? I think these also were partially glued in from the factory. I seem to remember seeing some adhesive on the under hood when I replaced mine.

 

I'm also from the school that says, if it had one in the past, it should have one in the future. I'd get a good one, though, such as the molded unit sold by Fusick. They aren't cheap but I believe they are well worth it in appearance alone. There are generic underhood insulation pads as well that are pretty inexpensive but I just don't like their looks. From my experience, the underhood insulation is primarily for engine noise reduction. I don't know if it serves and fire protection qualities or not.

I believe Olds put the underhood insulation on most or all of their cars back in the time - not 100% sure on that but all that I've seen either have their original hood insulation or it has been replaced.

I also have a '70 GTO and I know for a fact that it did not originally have hood insulation (nor does it have it now) and the engine definitely is a bit louder when you are outside the car. It also originally came with one of those flex fans which really made it loud - I kept the original flex fan but replaced it with a clutch fan to reduce that noise.

Items like this may have been a function of the so-called "heirarchy" of the GM divisions. Perhaps Olds and above (Buick and Cadillac) got the underhood insulation, whereas those lower on the totem pole (Pontiac and Chevy) did not normally get them. Just a guess-I'm probably reaching deep for that one, too!

Randy C.

 

The type of car, stipper or luxury matters, as does personal preference. If you drive the car, the insulator will get oily and nasty, negating the positive of having it.