It's not the rods heh. I've noticed of late that I sometimes I get the odd knocking on boost if I'm sudden or build up and then nail it (overtaking etc). It sounds very much like knocking/pinking so I let off straight away when it happens of course. It's random, and doesn't throw a fault code that I can see (liquid gauge says it's all clear). The car's on 120,000km (75,000 miles) so not that old. Plugs are probably around 15,000km old iridium NGKs but might be worth doing - was going to get BKUR7ETs and change more often? Fuel pump getting tired? MAF is genuine Bosch about the same age as the plugs, same for the coilpacks (bolt downs). Checked for misfires, nothing. The odd thing is that it drives ok whilst doing this (as in, smooth), but does feel a little underpowered. Which suggests to me running lean. I'll try to run the AFR gauge more and see whether it is running lean. The ambients will have picked up a little recently (getting towards summer, today was 30+) which probably doesn't help, if it's pinking. I've been granny-ing it until I know what's wrong Any ideas what it could be?