Hi ,
just recently acquired a audi 1996 2.6L v6, at low rpm and speed it sounds like the engine is pinking. I use 95 octane gas as its most commonly available and what the engine usually runs on.

What might be a cause to the engine pinking at low speed?
Do i need to check the engine timing with a timing light - what do i look for?
Are there any common causes to this issue? and
how do i go about diagnosing / repair without access to the diagnostic tool?

thanks