You simply have a "stuck" sensor. This is a well known issue among many Intel 45, 32 and 22 nanometer processor, which includes 2nd generation Core 2 architecture, and 1st, 2nd and 3rd generation Core i architectures.
The Core temperature sensors are designed to be more accurate at higher temperatures to provide throttle and shutdown protection if an over-temp condition is reached. Some sensors just don't show accurate idle temperatures, and some are so bad they won't go below 50C.
Idle temperatures are of little concern, however, load temperatures are very important.
Aw, thanks you verymuch, and i have a question
So serious problems to the CPU lifespan?