Every engine on the road today that has a block mounted camshaft has lifters, be it solid or hydraulic. The general purpose of the lifter is to convert the rotational movement of the camshaft to the linear movement required for the valve train. There isn't a prescribed time to the life a lifter, but like all moving components in an engine they can fail over time. Lifter noise is often confused with other common noises, so its important to know what symptoms come from a faulty lifter. It's also important to understand how the valvetrain as a whole works and operates.
The Job of a Lifter
A lifter serves as the link between the camshaft and the push rod. As the camshaft lobe pushes upward on the lifter, movement is transferred to the push rod and then the rocker arm. The rocker arm pivots downward, working against the valve spring and opens the valve. A hydraulic lifter uses a cushion of oil, to fill the gap in the clearances of the valvetrain. As the Lobe pushes upward on the lifter, and clearance from wear and engine expansion is overcome by the oil inside the lifter, making it as if there is no clearance between valvetrain components at all.
Lifts can fail for a number of reasons. Sometimes, lack of proper lubrication from a gunked up engine will prevent oil from entering the lifter, essentially eliminating the oil cushion. This goes right along the line with dirt contamination in the oil and blocked oil passages to each lifter. The basic engineering of a hydraulic lifter includes four pieces: the socket, plunger, valve mechanism and body. If at any time the plunger becomes loose inside the body or the valve mechanism fails, the lifter can collapse and create chatter every time the camshaft raises the lifter. Lifters can also become stuck inside their bore during movement and prevent a valve from opening or closing properly. A failed lifter can cause bent push rods, damaged rocker arms, and even valve damage if a valve is stuck open during the combustion process.
Tale Tale Signs
Most can confuse an engine knock or even spark knock with a faulty lifter. The valve train in any engine is known for creating a ticking noise any time there is excessive clearance. The ticking noise of a lifter fault will come from mid engine level or at the very top of the engine below the valve covers. A sticking or otherwise faulty lifter will often result in its related cylinder misfiring and overall sluggish engine performance. In the end, anytime these signs begin to surface, it should be fixed quickly to prevent further engine damage and excessive repair bills.
Starting Up to Warm Up
Sometimes slightly clogged oil passages will cause lifter ticking for the first minute or two until the engine warms up. This happens because the oil is thicker when cool and as the oil warms it can work its way through clogged passages and the lifter can work as normal. In most cases if a lifter has actually failed or is worn enough to make noise, the noise will remain roughly the same regardless of engine temperature. On the other hand, if your oil hasn't been changed and has lost its lubrication properties extra chatter could be created from lack of lubrication. The same concept goes for situations where too thin of an oil has been added to the engine, preventing proper lubrication.