A heat shield in a car protects components near parts that produce significant and potentially damaging heat. In most cases, this prolongs the life of the car. However, from time to time, a heat shield will become loose and rattle, and will need to be removed to reduce noise levels. Whether or not you replace it is up to your preferences and the type of car you are driving. The shield is easier to access in older cars and trucks with lots of room under the hood and can be a tricky endeavor in newer cars with smaller engine compartments.
Find the heat shield inside the engine compartment. Its exact location will vary depending on your vehicle, but the shield is typically found close to the engine and is a sheet of metal.
Locate the oxygen (O2) sensor which looks like a small metal plug, cylindrical in shape, with a wire coming off the exposed end. Remove the bolt holding the O2 sensor's wire bracket with a drive ratchet and socket. Disconnect the sensor from the manifold.
Remove the dipstick from the heat shield by removing the bolt fastener with a ratchet fitted with the appropriate sized socket to fit the bolt.
Detach the exhaust gas line that feeds into the lower middle manifold. This is held in place by two bolts, usually a 12 mm and a 10 mm. Remove the larger bolt then loosen the smaller one and twist the line out of the way.
Work out the heat shield gradually, without damaging any nearby hoses or lines. Flex it slightly, as necessary, to remove it.
