I have a tomos targa lx with a biturbo. I get a small ping sound. It's definitallt the exhaust vibrating on the block. I do get a bit of oil leakage from the port of the block but onl a couple of drops a day. If I grab the pipe it does quiet. I can't get the nut to go on ant tighter with out the feeling I'm going to breack something. I check it every couple of days and they don't loosen. But it's still there. I put the biturbo on the second day I had it and can't remember what it sound like with the stock exhaust. Is this normal? Does anyone else experiance this? Any suggestions?