Quick question, should the shiny side be facing the engine or the hood?

It has to be correct because it channels out the water and will fix the water leak-misfire problem I've been having.

 

Shiny side facing hood. I'm still failing to see how heat /sound insulation has anything to do with water leaks..

 

Few people on this site believe me, but it's true. One member even argued with me while I was searching for the rain-misfire problem (before I knew what I know now) that it was merely a coincidence that the car misfired only when it rained (as little as it rains in san diego) and that this didn't occur until I removed the old insulation. All coincidence he said .

GM even said that they originally wanted the vents to be functional, but had problems with water leaks so just put plastic covers for the vents and insulation to cover the engine. Some engines are ok with water, ours aren't - v6 or v8.

So ok, maybe my wires somewhere have a weak point that they should not, and other people who've removed the insulation as well have no problem with water on their LT1's and 3.4/3.8's. I do, and I know that this is the fix. Caulking works but only temporarily, the factory solution is the right choice.

 

MarcR94v6:
You're right about the vents and water. The first time I opened the hood after a heavy rain the water streamed out of the insulation pad! If you're careful and thorough you can seal the inserts with silicone caulk. I pulled the pad and inserts to clean the surfaces and sealed them years ago ... they're still water tight. (have some Que-tips and toothpicks ready to clean up any excess that tries to ooze upwards!)
Good Luck

 

Just because it's the , that doesn't make it the right solution!
IMO. Having water collect on top of the insulation isn't any better than having a leak in the first place. I would fix the leak, whether I added the insulation or not.

 

^^True, poor choice of words on my part.

And caulking DOES work btw, only thing is it must be painted over to be permanent. If you are concerned about this keep in mind, it is not just the holes where the plastic vent covers go that leaks, but the entire metal scoops have places that leak around the perimeter where they are bolted in.