While just looking around around my truck the other day I noticed a large amount of bugs and debris trapped at the bottom between the front of the rearward most radiator ( main one I think) and the one in front of it. The best view is when you stand in the front of the motor, look down from the top through the 3/4in gap between the two radiators. I had close to a half gallon of bug piled in there.

I have always gently sprayed the radiators off from the front, where you expect bugs it smash into the radiators, but this is 3 or 4 radiators layers back. So I tried to finger out how they got there in the last 56k miles on my 6.7 diesel. That's when when I noticed they were forced in from underneath. The black rubbery material that connects to the inside of the bumper and curves upward behind the tow hooks, heater cord, and I assume is to direct air up to radiators. If you grab the top of this rubber flap, it has about one inch of loose material that when stationary is closed, but must open when on the freeway, trapping bugs in a bad spot.

Just thought I would share, seeing mine and clearing them out made me feel good for some reason. Though I don't think it will change the cooling abilities, it may have became a problem.

The neatest part was seeing bugs from the southeast, Utah, Arizona, California, Canada, Montana, Wyoming, and many other locations.

Check yours, willing to bet we all have our own insect stash.

 

Cool but I always thought that this animal of an engine just ate them, lol.

 

Yeah when I pulled off my OEM front bumper the rubber piece went with it and it had quite the collection.

What that rubber piece was nice for, in the winter I would drop a coroplast political sign in that space between the rads and it was like having a winter front without it being visible.