Even in the months where temperatures are cooler, heat is still an enemy of your vehicle. When your engine runs, it creates heat, so there are numerous heat shields that protect other parts from those higher temperatures. Heat shields are installed around several areas of the exhaust system. Others prevent heat from reaching parts of the vehicle. Still others prevent heat from reaching the ground (or maybe grass underneath) and starting a fire.
If you remember your space travel history, you’ll know how important a heat shield can be. John Glenn was the first American to orbit the earth, but during that maiden orbital flight, a sensor on board was indicating the heat shield on his capsule, Friendship 7, was loose. If it had come off, his spacecraft could have burned up upon re-entry. Fortunately, the heat shield stayed on, and Glenn made history.
Unfortunately, the heat shields on your vehicle don’t have warning systems like the space vehicles did. So you have to maintain them. Heat shields are constantly exposed to elements like water, salt, sand and dirt. That makes them prone to rusting and corroding. Here’s one unfortunate fact: Materials that make them good at preventing heat transmission also are soft and vulnerable, often aluminum or special fabric.
One sign a heat shield will give you that it’s loose is noise; you’ll sometimes hear it rattling underneath your vehicle when it’s running. One way to locate it? Put your vehicle in park, leave the engine running and take a listen outside. It’s usually pretty easy to pinpoint the location.
Make a note of the noise when you are talking with your service advisor. It’s important to have those heat shields working correctly so the heat is kept away from your other vehicle systems and combustibles on the ground. The good news is that heat shields can frequently be inexpensively repaired or re-attached. In other cases, they should be replaced.
Missing or loose heat shields? Let’s just say they’re not cool.