Van tapping noise when accelerating

Tapping on acceleration sounds like it could be emanating from inside the engine. There could be a lubrication issue inside one or both of the cylinder heads, or in the base engine area. Of course, it's difficult to say without hearing the noise and doing a hands on diagnostic test. Seek guidance from a local technician near you. https://repairpal.com/chevrolet-within-10-miles-of-florissant-missouri-63031