Hi all, this is my first post on here.
I own an '88 Celica SX (ST162 motor) and have been having pinging problems with it for ages. I've taken it to a few mechanics and they can't seem to help. The last guy changed my timing to stop it (99% gone but car feels wrong to drive). Before the timing change, it used to occur after 20 minutes of driving REGARDLESS of the petrol. It started in 3rd gear at around 2200 revs and worsened at about 2500 - 2700. It was shocking on hot days and up hills. What could be causing it?? I've read that a malfunctioning EGR valve might be it (the last mechanic dismissed this without even checking). Could it be the knock sensor? The only thing visibly wrong with my engine is a cracked air intake pipe which has been sealed and taped up. I would realy appreciate any help on this. Even a recommendation to a great mechanic in the northern suburbs that might have a clue...