Ok this comes from timing chain, i don't know why the chain has those little (whatever you call them) installed in chain links and i am not sure if they come from my chain or it is just a left over from previous chain although i don't think so. There is a small hole next to the oil pump from where i can inspect the chain and see if it is missing from this one. In a case it is missing what do you think i should do? Shall i open the chain cover and replace the chain?:bang: