thanks for your reply Veteran. i use coretemp as well.
i also found out that the T case specification si later explained in a doc (http://download.intel.com/design/processor/datashts/31327807.pdf)
section 5.1, and sais that if you go above the Tcase temp limit (which is 61 for me), permanent damage can occur.
at this moment it seems that lot's of things could have gone wrong, including,as i hear, the tension stabilizer or something like that, or the thermopaste
i think i'll go into a service..
if you still have an ideea please share