noises

hi all.. on my c20let i have a big knocking noise its like a single but fairly hard sound from the top end somewhere, i checked the timing, checked cams, lifters (5 were moving so replaced with spare 1s i had now all solid) was running ok before this happend.. also had spark plugs out this...

I've recently fitted an Amp to run my 6x9's (just an old cheap one kindly donated by my step-brother) this is it: but since doing it, when the H/U volume is turned down or on low i get strange noises through my speakers. 1. A noise from the fuel pump priming on ignition 2. A horrid...