While idling there is a ticking/tapping noise from engine

Can you get a recording of the noise? That will help us figure out possible causes. However, from what you are describing this sounds like a possible bearing tick. If this is the case then it will develop into a knock.

So if this is what this is, then it is causes by lack of lubrication or excessive clearance between the journal and bearing. So what happens when you accelerate is it puts more pressure on the bearings and the noise stops.

I say all this because if this is the noise, then I would not change the oil right now and switch oil weight. I would find an oil additive that will thicken the oil. Then check the oil and if low, top it off with this product.

If the oil is not low then you will need to change the oil and just use the correct oil but add one of these additives in place of one or two of the quarts of oil.

If this makes no difference then you may have a valve train issue but that is normally not heard toward the bottom of the engine. That is towards the top and will normally get faster when you raise the RPM.

Let's run through this and let me know what happens with this and we can go from there. Thanks