Thanks KT
Hmmn, seems like a workshop diagnosis is the best for me. Things you've done, i not done them for quite some time so shall proceed to have them checked.
I recently asked my wife if petrol prices went up cos been topping up more often nowadays, since you brought it up, think mine's affected as well. Please update on your flushing & oil change results if possible, many thanks! Oh...and also the workshop that you use. Cheers!