Dear mustapha , there is certainly something wrong with your cooler , maybe thermal pate , maybe fan curve, or with you settings , or maybe it's just a very cheap one, that just does the job but not greatly... 87° btw is hot under load but it's far from abnormal regarding some coolers ... your cpu overclocks until it reach the throttling temperature , about 90 ... so the best way is to check your cooler
and , you don't need to post same thing two times, you can edit