This is really odd.

I was driving to the Dick Smith store and the car was fine. I even took a hwy so i can boot it a little. I got what i needed and started going home. I get on a main road and what does my car start doing ? it starts to ping very loud and noticed the temp going up and up.

I pull over in a parking lot and notice the fan aint kicking it. I held the revs to 2.5k the fan kicks in so thats ok.

I let it cool down and it starts pinging again no matter how i drive it. I stopped at supercheap and picked up some coolant just incase ( *** expensive too )

I take off, cars still running rough. Then for no apparent reason, temp drops back to normal, car isnt pinging and has regained some power.

WTF just happened ?

Sorry for the long story lol.

Pinging... timing problem, or something is obstructing your engine somehow, check that oil cap for milkyness (my recommendation to everyone lol ) Water pump might need to be checked, or your radiator is having dramas, blockages etc. Check spark plugs too, dizzy etc.

Possibly it could be sticky thermostat, temperature sensor playing up, fan switch playing up, ECU pluying up or loose contact somewhere along this path.

Yeah thanks ill have a look at the car when its a little cooler. Also, i have noticed white stuff on the battery and has eaten away at the battery clamp's paint. My bro said he needed to give someone a jump start the other day. Do you think it could be related ?

Yeah thanks ill have a look at the car when its a little cooler. Also, i have noticed white stuff on the battery and has eaten away at the battery clamp's paint. My bro said he needed to give someone a jump start the other day. Do you think it could be related ?
doubtful, that's probv just corrosion on the battery terminals.. disconnnect the battery and clean that up asap

Also if its white stuff, just pour boiling water over it, it'll instantly disolve it

not flaming but why is it that when ever anyone has any issue with a car you all just go straight to the head gasket?

The engine will tend to ping when the temp is high. The only real suggestion here that makes any sense is the thermostat if the levels are ok, that is assuming it is not a recurring problem of course.

Sensors.....no as the engine temp will not rise that far and fast for even a lean mixture.

Replace your thermostat, the fans are no issue when you are moving so do not even bother to look there. If your engine is ok now then forget your head gasket, the only way a blown head gasket will make it ping is if a bit is broken and getting too hot, this generally will not be detected with oil contamination either