Engine pinging/pre-ignition cause?

[SROK]

Anyone experienced any symptom (besides the obvious sound) and can an OBD check confirm that the engine is pinging?I have discussed with many a workshop and some said that obvious causes is due to the knock sensors, faulty O2 sensors... surprisingly some even told me that instead of being a pinging problem it could be the vanos (but is that not a whining noise rather than like ratling coins??)

 

[Mouse]

could be using the wrong spark plug (wrong heat range). have u recently change to a new plug brand?

 

[SROK]

Have checked and it is not the ignition cables nor the spark plugs. Have been using Brisk plugs and they are great all these years.

 

[turbology]

faulty injectors ?
carbon build-up ?
ailing MAF?
wrong fuel ?
bad fuel pumps ?