Rattle

I was driveing my car and i notice a loud rattle... i got out poped the hood... and about ever 5 sec i hear a knock... and it was way to loud to be in the block... so i towed my car home... now when i start it and stis it wont make the noise until i give it like 3000 rpms and it will barley make it and its very quite. and it seams i have a exhuast leak some wear but that aint the noice im hearing... think mabey a blew up a turbo? or floated a vaulve?

Dunno, rattles are a PITA. Could just be a loose bolt or something. When I redid my oil cooler, I didn't have it secure enough, and when I drove it, it was rattling...scared the hell outta me. I'd suggest going over anything you have recently worked on, and just making sure everything is tight and secure. That at least will be a good starting point.

true but when it makes the rattle noice it shoots out white smoke from the back of the engine...

white smoke in general usually has something to do with the valves, so that may be your problem.

true but turbos also cause white smoke...
heres my conclusion... it idels perfectly... its it was in the vaulve train it would sputer and knock constantly... the rattle is rpm based if i give a little rpm it rattles barley, which tells me it aint mechanical. when the engine heats up alot it gets louder... turbos will start to loosen up due to heat. some where i have a exhaust leak in the engine bay... im beting its the turbo... mabey the turbo houseing broke and the shaft came loose and that and the bearing are rattleing around when i give it some rpms. so what i plan to do is get a compression tester and test my compression... if everything comes out good then i will know its not the vaulve train...

i dont know. same thing happend to me. a slight rattle only around 3k rpm. thought it was nothing because it was little and only around 3k rpm. left it alone for about a week. got a little louder. the good news? turns out i threw a rod bearing. the rod was knocking. got the engine rebuilt for $3600. didnt just want to put the bearing back. it wouldve been a shame not to rebuild it. i thought it was a turbo too because thats when the start to really spool and hold boost. so wrong was i.