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.
Customers may complain about a ticking noise, engine misfire and/or SES light. This may be the result of an AFM (Active Fuel Management for displacement-on-demand) lifter that unlocks as soon as the engine is started or one that is mechanically collapsed/stuck. This TSB applies to the following vehicles: