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.
Hydraulic Lifter Noise â The Fix. When it comes to building engines, those equipped with hydraulic roller lifters offer major advantages to budget-conscious car crafters. Starting in 1987 with passenger-car small-blocks, including the Corvette and Camaro, Chevrolet began gearing engines with hydraulic roller lifters and cams.