I know Ford went to the trouble and expense to put it on there. I always say if they could have saved a dollar on each truck they would have.
They did "Saved a Dollar" here and there - like the hood-to-cowl seal sucks and dumps all of the water off the ends into the engine compartment. They saved a dollar or two on that one.
Hood Insulation: Here is another possible concern of perhaps considerably less importance. I don't know if Ford engineers were also thinking of this.
Technically: Warm air (in the engine compartment) holds more moisture (humidity). When the engine is turned off this continues but there is no forced ventilation (fan, and air entry through grille while driving) to displace the warm humid air.
When it is cold outside, the steel hood will cool very quickly and often reach the "dewpoint temperature" causing the moisture in the warm air to condense under the hood.
Like this simple line - from wikipedia:
>
At temperatures below the dew point, water will leave the air. The condensed water is called dew when it forms on a solid surface. <
Hood underside could get quite wet depending upon relative humidities and temperatures of outside air (and what's happening in engine compartment) but it's complicated for me to to discuss it here.
This effect would stop after the engine compartment cooled down to match outside temperatures.
When you see condensation all over your vehicle while parked late at night/early morning this is the same effect from the opposite direction, moisture laden air passing over the cold surfaces of your vehicle -- however for a longer period of time than the effect in the engine compartment that I'm talking about.
So, what happens with the hood insulation? 1) The engine side surface acts as a (good enough) vapor barrier blocking moisture in the warm air from reaching the hood where it can condense as water AND the
insulation itself is very important part of this - it prevents the lower surface of the insulation over the engine from getting cold and condensing moisture (it's now warm insulation surface) And at the same time it reduces heat transfer to the hood = if the air next to the hood gets warm, IT WILL contain more moisture- the vapor barrier surface on the insulation is not a complete seal. Without the insulation the vapor barrier would condense moisture.
So is that a possible concern? Rust forming?.. on parts under the hood? Technically speaking it could be. In warm dry climate, not much concern... in colder wetter climates with higher humidities cold rainy days (high humidity)
maybe a concern.
What do I really think about this? Very small technical thing, of concern or not, it's one more small reason to add to the big reasons for keeping the hood insulation intact. The big reasons have been mentioned. they are:
1) Quicker engine warm up- quicker heat into the cab when it's cold
(I like that).
2) NOISE INSULATION. This was a very big deal with IDI's at some point and it was addressed. My 87 has insulation on the firewall and the inner fender wells. (it's still loud and I think the old lady across the street doesn't like it not matter what time of day or night) This is not just a problem for people inside the truck, it's more of a problem for people outside of the truck, like your neighbors early in the morning or at any time for some neighbors. A neighbor on a second floor above you truck is going to notice it more with no hood insulation - plus the extra noise will bounce off houses and the truck will be louder.
For all of those reasons I WANT to keep the hood insulation.
Lastly, I have broken clips too. I bought the biggest ones I could find after checking parts stores. They were GM. Did not find any big ones for Ford. These did not hold well and lasted only weeks before they popped out - the holding pins are a bit too small. So, if I can't find proper ones for Ford, then I will GLUE THE HECK out of the GM ones to get them to stay, maybe use a thick hardening gasket sealant or gasket maker from a tube - whatever works.
Sorry this post was a bit long. My knowledge about insulation, vapor barriers, effects, etc. comes from some technical work I used to do relating to commercial/industrial buildings, earth sheltered homes, etc. where humidity control is very important (even in yachts and probably submarines) I like to pass on knowledge whenever I can.
