Bobby 4/14/2010This sounds pretty severe, especially the metal clanking, has it possibley jumped timing? or has anything else happened with the vehicle recently? overheated? ran low on oil?
gwynne 4/14/2010how many times have you let it run hot ??? do you see smoke in your exhaust smell antifreeze???
HouseCallAuto 4/14/2010Maybe a clogged catalytic converter. That would give a wheezing noise of escaping air because that is what it is doing. Exhaust pressure builds up and cannot exit the exhaust system because of the restriction and the result is stalling after warmup and the definite sound of air escaping through any place it can escape from which takes a few seconds after the stall. Try removing the most forward oxygen sensor (before the cat) and then start it up and see if it alleviates the problem. Do this only if you think my advice fits.