I have an 06' FX4 screw. I had been noticing a hissing noise coming from under the hood for a few days. I thought it was the airconditioner making a funny noise so I ignored it. I had the check engine light come on. So after a few days it becaming annoying so I looked under the hood again to see what the problem was. I noticed a bunch of that tin foil looking stuff torn off behind the engine (not sure what the technical name for the stuff is). As i began looking further into the engine, I noticed that it was piled up. I am attending college and I wasn't near my local dealership, so I had to take it to the dealership in town(town is about 4,000 people). I had the guy at Ford look at it and after about 20 minutes he came and told me that an animal had crawled inside and made a nest and chewed on the vacuum tube. I looked at him like he was joking with me. This had to be the most outrageous story I had ever heard. I asked him how much it would be to replace the problem and he couldnt exactly tell me. Neadless to say I was very upset. I was even more upset when I found out it wasn't covered under warranty because it was an animal that caused the damage. I came back the next day and had him fix it. It cost me about $70. Now I am not sure to tell if the "animal" is gone. Is there any way to find out without tearing apart my engine? Also that tinfoil looking stuff, where can I replace this part? Thanks guys.