There are two major heat shields on the bottom of my 2006 Ford Focus. The one near the muffler and the fuel tank is OK, but the big one spanning nearly the entire length of the car. It is huge. It starts from just behind the powertrain to nearly the end of the rear passenger seat. The heat shield had been secured with small screws, but the aluminum heat shield material has been torn off around the screw.
What would be the best way to reattach the heat shield? I cannot reuse the existing screws, because they are rusted, and the heat shield is torn, so I cannot screw them onto the same spot.
What kind of screw do you recommend? Can I make holes into other parts of the body? What precautions should I take before putting additional holes into the body (such as preventing new rust, preventing them from loosening)?
Heat shields can be tricky to reattach once the flimsy metal that makes up the heat shield rots away.
Sometimes the heat shield can be tack welded, sometimes self-drilling screws can be used, sometimes rivets can be used, and sometimes you just remove the heat shield and don’t worry about it.
If the heat shield is between the hot parts and car body then the concern is starting the car on fire not grass and leaves. I would fabricate some small metal tabs that would be screwed into the existing holes and rivet them to the closest solid part of the shield. You can get replacement sheet metal screws at the hardware store and if you don’t have one, a cheap pop rivet gun comes with a small supply of rivets too. Pay a little more and the gun head pivots 90 degrees making it easier to reach in.
Have A Look At Fender And Area Washers, Also Pop Rivet Tools.
If You Don’t Own A Pop Rivet Tool And A Selection Of Rivets (With Different Diameters And Grip Ranges) This Could Prove To Be The Perfect Excuse To Get One. You’ll Need Your Cordless Drill, Too.