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Firewall & underhood insulation?

Discussion in 'GM 6.5 Diesel Engines' started by Tookie, Apr 19, 2010.

  1. Tookie

    Tookie Member

    I know this is not the forum for this, not sure where it goes.
    Where can I get replacement insulation for the firewall?
    Between motor / bellhousing and firewall. I also need to
    replace the insulation on the hood.
  2. Pruittx2

    Pruittx2 OBD 1 Master

    May 6, 2008
    Lake Odessa, Mi
    the last I heard, someone on here had bought the last of the GM factory firewall insulation for a dealer in Texas, you could as your local chevy dealer to do a nation wide search for the part number. the hood blanket should be available from LMC trucks.
  3. WarWagon

    WarWagon Well it hits on 7 of 8...

    Nov 15, 2009
    Just remove it. When soaked in oil esp around the oil cooler lines and exhaust it becomes a fire hazard. It has not made any difference in heat or sound on mine. I left the hood insulation though. But the 2" thick of cr@p missing from the firewall makes getting to the transmission bell housing bolts easy.
  4. bobbiemartin

    bobbiemartin Author of The DB2 Conversion Guide

    Sep 25, 2009
    Jacksonville, Florida
    I bought the factory insulation pad from the dealer. Its not the same as what was on the truck originally. Even though its was genuine GM, I don't think its as good as the original pad. If I had to do it over, I would use Dynamat Hoodliner. Its cheaper and probably easier. BTW, you will never get the pad replaced unless the engine and most everything else is out of the way.
  5. Tookie

    Tookie Member

  6. WarWagon

    WarWagon Well it hits on 7 of 8...

    Nov 15, 2009
    X2 on engine needing to be out to replace it. But to remove it can be done with the engine in.

    And it makes a big f'ing mess when all the plastic and insulation falls apart while getting ripped out.
  7. JMJNet

    JMJNet Recruit

    May 6, 2008
    Richardson, TX
    My firewall insulation is all ripped in convenient places. At the beginning I was worrying, now I just live with it. I bought the kind that has Al on one face and insulation on the other side from JCWhitney but never install it.

    I guess, it needs to have the engine out.

    The hood insulator is intact but I don't think it is new, though.
  8. SmithvilleD

    SmithvilleD Active Member

    Mar 2, 2009
    Smithville, MO
    I removed the insulation covering most of the firewall (fender to fender); it was falling apart as is prolly common w/ many of our trucks. I then covered this area with "peel-n-seal". The smaller/separate insulation just around the bellhousing area I covered in Al tape (like used to seal hvac ducting) to hold it together enough to be re-used.

    Peel-n-seal is intended as a roofing patch material & comes in a roll & is a thin asphalt layer with Al foil backing & the asphalt side has an adhesive. This product has been used by car audio enthusiasts as "poor man's dynamat".

    I can't provide any head to head sound damping comparison to dynamat/hushmat, etc.,. But can say it quite noticeably quieted my truck's interior when I put down 2 layers to the cab floor before new carpet. I put it on the firewall because it was easy w/ the engine out & wouldn't absorb oil/fuel etc. Do think it would look better if after applying the peel-n-seal, I'd sprayed the Al foil outer layer w/ a black product like Lizard Skin.

    I suspect the open, fibrous nature of the factory firewall & hood insulation is likely to be more effective at keeping engine noise out of the cab. But replacing the factory firewall insulation means work beyond just pulling the engine as I'd imagine Bobbie can attest to.
    Last edited: Apr 21, 2010
  9. Acesneights1

    Acesneights1 New Member

    May 5, 2008
    Northeast CT
    Hahaha...Try driving a CUCV. 6.2(same as 6.5) No insulation at ALL. talk wabout loud..Damn.

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