Are those thin aluminum heat shields that look like disposable roasting pans really necessary? The one midway along my 4Runner is making a racket. Can I just rip it off?
I recommend securing it with a large hose clamp from the hardware store. The heat shield is there for a reason, to prevent fires. Removing it may or may not result in a fire. Why take the chance?
Yes. You can remove it if there’s nothing left of the heat shield. I’ve removed a lot of heat shields from vehicles because they made noise and I’ve yet had a report of a fire being started because the heat shield was removed. If you look along side the highway you’ll see heat shields that have fallen off vehicles and owner doesn’t even know the heat shield is missing.
Ideally re-secure them, often a hose clamp will do the job. It can be easer than removing them. If you have to you can remove them, but watch for for overheated floor pads. or if you park in tall grass sometime, watch for fire.
I attended a motorcycle race at Laguna Seca raceway many years ago and a Firebird was parked in tall grass near where we were standing. A grass fire started beneath the car. Fortunately, someone noticed, and many race fans tend to carry fire extinguishers in their cars, so it was put out before the car was lost or worse.
These days, it is hard to know what is really ‘necessary’ because designers have to add so many things just to make it look like they were taking every precaution to protect themselves from frivolous lawsuits. Look carefully at the heat shield and at nearby components (including undercoating and flammables inside the car attached to the floor) before deciding it is unnecessary.