Here is some info about what is a lifter and a possible soultion .If the problem is lifter tapping immediately after cranking the engine, the oil check valve in the cylinder head may need cleaning. Page 17-10 in the shop manual covers the procedure.
The check valve is simply a spring-loaded ball in the oil feed line that prevents oil from draining back while the engine is not running. If this check valve doesn't do its job, the oil lines in the head will be empty, and they will require a few seconds to fill when the engine is started, causing lifter tapping.
The valve is located inside the valve cover, at the lower front corner of the head. After pulling the valve cover and finding the valve, locate the locking screw]\ that goes in from the outside of the head to the side of the valve, and loosen it about four or five turns. Screw (by hand) an M6x40 bolt gently into the valve spring guide (the only part that you can see) until it bottoms, then unscrew it two turns. Pull the spring guide out. Using a magnet, remove the spring and ball. Clean everything, being especially careful to avoid damaging the ball seat down in the hole. The book says to replace the o-ring, and it would be a good idea to do so, especially if it is hardened.
Reassemble. The threaded rod that screws into the side to retain the valve should be tightened to 2.8 ft/lb, which isn't much!
Engine Tapping Noise
Tapping noise from the engine is often caused by a stuck hydraulic lifter. A bad lifter is not necessarily a huge problem and if you are driving an older vehicle you may wish to just ignore the noise if the engine is otherwise perfoming well. Increasing the frequency of your oil changes may help to clear up the issue but if the noise persists you will need to replace the lifter to eliminate the sound.
The above noted, if your tapping sound is accompanied with engine vibrations or backfires, you may be facing a problem more serious than a stuck lifter.
1. Tapping and Vibrating
If the tapping in your auto's engine is accompanied by a persistent vibration or noticeable tremors under load, you may have damaged the rocker-arms or valve push rods. To check the problem you will need to remove the valve covers and visually inspect the arms, rods, and valve stems. Oftentimes the repair is nothing more than replacing the broken rod or arm and bolt.
2. Tapping and Backfire
Though much less likely, if your auto happens to also be backfiring while tapping, you may have a damaged camshaft. This will not be something you should attempt to diagnose yourself, and it will be a fairly costly and laborious repair. If you suspect a bad camshaft, take your auto to a reputable mechanic or dealer and get the cam tested. Before leaving your vehicle, get a full estimate (in writing) and for the repair itself, and for the testing and reassembly should you decide to decline the repair.
If you do go ahead and replace the camshaft, you should also replace all of the lifters as well. Further, this is an opportune time to replace your timing chain or belt.
__and this is what it possibly could look like.
Good Luck ,At least I learned something