[mk_sentra]

hi all
i hear a pinging sound when i turn on the AC (mostly accurs now) and sometimes while running normally.

do i need to get the fuel injectors cleaned/flushed or can i add a bottle of prestone fuel system cleaner to the gas tank?

thanks
mk

 

[SergioCR]

I used to have that problem but fixed it with a timing light and some street test... maybe you have the timing advanced and when the engine has more load starts to ping, if it doesn't stops after the timing is adjusted it may be needed to check and adjust the valves clearance.