348/355 Rear Deck Lid Heat Shield Replacement - HOWTO

Major cabin fever times in Indiana. So time for another project.

Today, a step-by-step guide how to improve the look of your 348/355 by getting rid of that nasty crumbling foam insulation on the underside of your engine decklid.

You will need to order some aluminized heat-shield material. I got some from Summit Racing or see Step 8 of this write-up for an alternative easy option.

The material is dual faced with about 1/2" filler. Just about the right thickness and looks very OEM.

1. Call your son away from the computer. Tell him enough of Minecraft/Roblox/Call of Duty for the day and have him help you for step 2.

2. Unscrew the 4 10mm screws supporting the rear deck-lid. Have your son help you CAREFULLY lift the deck-lid away from the car and have him help you guide you with the deck lid into the house.

3. You have many options for working on this. Suggestion include: your master bedroom bed (especially if your wife JUST put new sheets on), your foyer floor, guest room or, my personal favorite, the dining room table. Does not matter really; you are bound to get a fair amount of crap from your wife anyway for bringing the "nasty car stuff into the house."

4. Remove the old foam by simply pulling it away from the deck-lid. You may use a plastic spatula to help lift it from the edges. Vacuum old residue. Note, it is sticky nasty stuff. Alcohol helps remove it from hands, tools, etc.

5. Use the old removed foam as template and cut the new material. HINT: if you cut the smaller piece slightly OVERSIZE (like we did), you will NOT have to use any glue to re-secure as it will be nicely wedged and supported by the metal channel-work. Your wife's utility scissors work great for that task.
There should be enough residue from removal of the larger piece that you will just be able to stick the new piece right to sticky part. If not, you will need to buy some spray adhesive (Summit sells it as well). We did not use any additional glue.

6. Install the cut pieces by sliding it from center and then tucking the right and left sides.

7. Have your son help you re-install the deck lid. You may have to play a bit with alignment to make sure it closes evenly. ENJOY a job well-done.

8. Now, here is a plug. My son Alex who is 13 and a budding entrepreneur and Ferrari enthusiast decided to sell these at a nominal price to all you lazy ones that do not want to go through hassle of ordering the material and cutting it to size yourselves. So PM him (AlexWJD on Ferrari Chat), and he will sell you the two pieces cut to size perfectly (his Dad will supervise and control quality) based off the original Ferrari templates.
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Great post, looks cool...I may do this very soon.

All cars have that or another type of foam over the engine lid. Is the purpose noise reduction, protecting the paint? Why do they put that stuff there anyway?

 

On "regular" cars the purpose of this material is mainly noise reduction and probably heat control too. But, with the omnipresent cost reduction in the auto industry, I noticed many, even premium brands, skipping this entirely nowadays. For instance 2008 BMW 3-series had that, couple years later it was gone completely.

 

Nice job Bart!

That insulation goes bad on so many cars. I replaced mine several years ago with some aluminized heat shielding, similar to what you did.

 

Now, remove your wire mesh under the louvers. A couple fasteners, drill out a few rivets, voila. You'll be so pleased with the appearance and the ability to clean both sides of your louvers.
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My 355 has no such padding of any kind on the rear deck lid

2.7 motronic 1995

 

I think it should... mine does.

 

mine too

 

When I got my car it was awful so replaced it with some heat/fire resistant insulation. It was self adhesive bt it started coming away in a couple of places so bought some secial sealant/glue they use to stick the rubber gaskets round oven doors and it holds just fine now
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FYI: I have about 6 - 12 ft. left of the foil lined engine compartment insulation leftover after mine was done. J.C. Whitney supplier made me buy a whole roll of it. I have supplied a few other Fchatters for their fixes. If you PM me we can figure out a reasonable
deal for your needs. It will also clear out room in my garage & that keeps me out of trouble with her highness.

 

My old car didn't have the insulation at all. There were zero problems with it - no paint discoloration, etc. In fact with the lack of insulation, the heat dissipated a lot better.

 

No insulation on mine either (95 F355). On the 355 the only spot to even apply insulation would be at the front-most part of the bonnet and that's only about eight inches wide. Not sure that there would be any benefit there.

 

You 355 owners are probably victims of Ferrari cost-cutting - hence no insulation. LOL.

 

Be aware that this black type of insulation also deteriorates with time (crumbles away). I much prefer how it looks but the reason we went with the silver stuff is it does not seem to degrade much with time. Just FIY...

 

Nah... I like the mesh.

 

My foam was hanging and sagging. I thought that I would just pull it off, until I found a reasonably priced replacement. I was thinking about using material from a supplier in the back of Hemming's Sport and Exotic. They sell under hood insulation with British car logos, etc. The description sounded similar to the OE foam.

When I started pulling out the old foam, I noticed that the backing panel was some type of black textile material attached to fiberboard. I took a plastic paint scraper, and removed all of the foam from the backing. I used Goo Gone to remove the adhesive from the backing. It really looks good. It looks much better than the gray foam.

 

I actually replaced my heat shielding over the weekend as well. After searching for a product for several days, I found this:

Thermo-Tec : Cool-It Mat

It is available in a size that is just enough to do the trunk lid about 1 1/2 times, so you'll have plenty and some left over just in case.

Used 3M adhesives to attach, and so far, so good.

g77: That does look pretty nice. How does it look with the deck lid open? My oak tree LOVES to cram leaves down in that mesh grate. Drives me bonkers.

 

Volair, very nice job.

 

unable to send a message to AlexWJD, I tried, said he wasn't setup.

Exact error:
The following errors occurred with your submission:
AlexWJD has chosen not to receive private messages or may not be allowed to receive private messages. Therefore you may not send your message to him/her.

 

Send an e-mail, not a private message. That is what I did - no problems. The heat shield pieces are cut very well and I think worth the nominal cost.

 

What functional differences would there be between the factory foam (which wouldn't reflect heat), reflective metal insulation, and no foam?

Does the foam matter during driving, when there's presumaly air circulating around the decklid, or is it more for when the car is sitting?

If the 355 lids can do without insulation (no danger to the paint, etc.), is it safe just to peel the dangling foam off my 348's lid?

 

This stuff is great and I have used it on my Miata for years. The reflective foil helps shed heat and keep away from important surfaces like the body paint.

 

I look at it from the perspective that the factory used absorbent foam versus reflective. Heat can do some weird things, especially over time, to the electronics. Talk to a 355 owner. I would rather use the stock insulation over a reflective surface. It this works for you in the long run, great. I personally like the way my engine bay is cool.

 

Interesting. My 348 has the gray foam. May be original or replaced by dealer. I did take a piece of the reflective type that I had in the hood plenum of my Miata and set it on the muffler shield right in front of the tail lights, hanging over a bit on each side. I just had my passenger side stop light go out and saw the connector was loose and the bulb socket was also loose. I thought it had cracked the housing on one side but after further inspection it was only chipped a little. I don't think it was installed properly years ago. So it's back together with an extra layer of electrical tape around the socket seal, at the housing, with the cover on top. The insulation sits a inch or too in front of that right on the heat shield. There is room for air to circulate but it will keep some of the heat from the lower shield and cat pipes below from radiating directly on the tail light covers.

 

Under the Hood Foam Reduces Engine Noise - Automotive Solutions

This company specifically makes foam to reduce engine noises.

Since I'm driving a Ferrari, I want the reverse of that. Therefore: the foam is bad and I should remove it.

Just like that stupid plastic box that silences the intakes.