Insulation around engine bay...? (Page 1/5)
CSM842M4 MAR 16, 06:52 PM
While pondering building a replacement battery tray to replace the rust-eaten factory unit in my '86 GT, and looking for locations to secure it, I noticed that the front and sides of the engine bay are covered in the type of insulation normally found under the hoods of lesser automobiles. The purpose for this insulation, other than on the front wall, eludes me. Seems like it would best serve to trap water and assist in the rusting process, and that it could be replaced with a coating of some product like Lizard Skin (I promise this is not an endorsement or advertisement!) after the new battery tray was installed. Unless there's something I'm missing, which is entirely possible. Any input on this topic would be greatly appreciated. Thanks in advance - Chris

[This message has been edited by CSM842M4 (edited 03-16-2019).]

06GTO MAR 16, 07:00 PM
I think if you search, you'll find most people remove it. I can imagine it serves a purpose though. I removed mine.
Egor MAR 16, 07:26 PM
I have found that it is great for rats to build nests on top of the manifold.

After a large amount of cleanup, I went with after market heat and sound deadening over the entire firewall.
Much better.

Egor

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"Of all the things I have lost during my lifetime, I miss
my mind the most."

Spadesluck MAR 16, 08:09 PM
Ripped mine out completely when I had the motor out. 30 years of dirt and grime that stuff was disgusting.
Patrick MAR 16, 09:34 PM

quote
Originally posted by CSM842M4:

I noticed that the front and sides of the engine bay are covered in the type of insulation normally found under the hoods of lesser automobiles. The purpose for this insulation, other than on the front wall, eludes me.



I believe it's primary purpose in the engine bay is for sound deadening. It's secondary purpose is to irritate the skin of anyone working around it back there.
CSM842M4 MAR 16, 09:50 PM
Think I gotta go with Patrick here, if only from a personal historical standpoint. All other responses also bear their own merit, though. And it sounds like it won't hurt a thing to pull it. It will pain me to alter the VERY stock nature of this particular car, but since I'm not putting a stock battery tray back in it, I guess I'm already going to do that... If I can remember to take pictures AND figure out how to upload them, I'll happily share the results.
Rickady88GT MAR 16, 10:20 PM
I chose to take it all out and repaint the engine bay. The insulation plugs or restricts ventilation holes on each side. But I will say that the side may be for sound insulation, the front and rear need to have a good layer of insulation. I have seen luggage with melted and burned spots from being in the trunk.
Daryl M MAR 16, 10:46 PM
I plan on replacing mine with new and doing tha wall between the engine compartment and the trunk as well. I am also insulation the exhaust system. Keeping the trunk cool and the passenger compartment quiet is a priority for me.
Patrick MAR 17, 02:26 AM

quote
Originally posted by Rickady88GT:

...the front and rear need to have a good layer of insulation. I have seen luggage with melted and burned spots from being in the trunk.



With the trunk getting that hot, I'd be wondering if the factory metal heat shield between the muffler and trunk was missing (or damaged/incorrectly mounted and jammed up directly against the trunk).
Rickady88GT MAR 17, 08:14 AM

quote
Originally posted by Patrick:

With the trunk getting that hot, I'd be wondering if the factory metal heat shield between the muffler and trunk was missing (or damaged/incorrectly mounted and jammed up directly against the trunk).



On my last 2 engine swaps I doubled up the stock heat shieds. I used a heat reflecting insulation on the inside of the trunk under the carpet.
Through the years of searching wrecking yards for parts, I have seen several melted trunk carpets from the exhaust. The factory sound insulation under the carpet is discolored from heat.