Nissan Repair: 97 Nissan XE 4X4, dollar signs, oil additive

Question
Today my engine started making a ticking noise. Loud at first then softer and then loud again. The oil has recently been changed, and oil is reaching the top of the engine. I asked a local garage for an opinion had the mechanic said it was nothing to worry about that it was called a tappit, and could be solved by adding some sort of oil additive which he did not know the name of. I have never heard of such a thing. I fear I am going to throw a rod, and he knows it, and has big dollar signs in his eyes for when I do. How can I be sure what the problem really is? How do I fix/prevent it?

Answer
Hi Angie,

Tappit is a funny name for lifter. Since you just had your oil changed a couple things to look at. One, is it full? I know, had to ask... Second, what viscosity was put it? It makes a difference especially with the weather changing. Looking at Nissan I find nothing interesting other than 3 second valve lash on cold soak start up. In other words when it's cold in the AM. There is no additive in the world that will make this go away, no more than nasal spray cures a cold. I don't thing your in for a connecting rod failure, but check the oil and the viscosity. Let me know what they used.