If your car is a Non-turbo, this is very typical of a failed airbox thermostat that controls the hot or cold air intake. It has probably failed in the hot air intake only. That causes pinging under light loads, steals about 10% of engine power, and makes your mpg 15 to 20% worse. Easy fix. Search on the board.

Fixing the flap valve on the bottom of the airbox in the cold air only position works OK. You may prefer to replace the wax capsule that controls the flap valve though.

i've done all the ordinary cleaning, tightening, replugging, reseating plugs/wires, recent plugs, wires, rotor, cap, filters, seafoamed the intake, etc.

i need to replace the breather box and might do the knock sensors while im under the intake since it is such a long procedure to get in there.

the knocking/ping i am hearing is right around the RPM's i would hear my old ford start to knock during moderate throttle up a hill or something like that.

im puzzled... maybe im not hearing a knock/ping... what else would sound like that though...?
--
-woodsytf '95 850 wagon 160k

Hi there.
Is the engine overheating?? Just a thought.

best of luck.
Howard. Isle of Skye.

Have you tried any injector cleaner lately? Leaky intake manifold? Reseat the MAS senor plug.