Right off the bat, I am assumming that when you rev the motor up, the noise speeds up, as well. This would eliminate a rod knocking. I also would advise you to check the oil. The valves are the last to get oil, and if you are low, they will suffer. Next, smell the oil, on the dipstick. If you smell a lot of gas, then it might be time to change it. When you take shoft trips in your car, the motor does not fully warm up. So, it run rich on fuel, and more leaks by the rings, and into the oil, thus breaking it down, and hampering it's lubricating abilities. If it persists, after the oil change, then it is either an exhaust leak, or, a loose rocker arm. I would adjust the valves next, which is a good place to turn this job over to an expert. It get technicle from here on.
Bearing noise is usually deeper and comes from farther down in the engine. Lifter noise is more of a ticking and is up in the engine heads.
chances are good in your 1996 Chevy lumina if there is a slight tapping noise, check the oil. it may be low, or you may need to add a thicker additive. good luck!
hydraulic lifter? Rocker arm?
A tapping noise might come into the engine because of heat damage to the lifters of the motor. You might also hear a tapping sound if the engine has been damaged due to a blown head gasket.
98 Chevy new 383 block 30k, ticking noise from sounds like heads . 210k on heads;
Engine running hotter then 220 degrees can cause valvetrain noise. Bad fuel can also cause valve noise / PINGING sound. Ignition timing to high / Advanced to far, can also cause engine noise.
Exhaust leaks, bent pushrod
Stuck hydraulic lifter.
loose exhaust
Cold engine it's the oil filter, get a high end filter with a pre lube valve. Hot engine cheap or wrong weight oil, or, bad oil pump.
Most probably the noise is piston slap, this noise is heard when the engine is cold and disappears when the engine is hot. if the slap is very strong when the engine is cold and the noise becomes less when hot but still the noise can be heard.
possibly low oil or low oil pressure, the tapping may be coming from the oil operated hydraulic lifters.