You may be surprÂ­ised to discover that a carbon monoxide (CO) detector really isn't a complicated piece of equipment. Housed inside a plastic chamber approximately 3 inches (7.6 centimeters) in diameter are parts that work in unison to alert a househoÂ­ld when lethal gas is detected.
This type of noise is usually caused by malfunctioning valve lifters or an exhaust manifold leak. If the noise lasts for more than a minute and completely disappears or dimishes after the engine is warm, the most likely cause is an exhaust manifold leak.
Valve lifters are the rods running from the camshaft inside the engine to the valve train on top of the cylinder head. The function of a lifter is to follow the shape of the camshaft lobe, which raises and lowers the lifter, causing the valves to open and close with the proper timing.alve lifters are the rods running from the camshaft inside the engine to the valve train on top of the cylinder head. The function of a lifter is to follow the shape of the camshaft lobe, which raises and lowers the lifter, causing the valves to open and close with the proper timing.