I have HP Z620 and it had the E5-1603 and I swapped it to this one the E5-1660. The CPU temp is running high and wondering why? The fan used is the stock HP fan and it is rated for this CPU. The temp is 70C to 80C but mostly sits at low is 70C. The Tj max is 91. There is thermal paste correctly added. The PC has been running for over 15 hours so far.
Re: "There is thermal paste correctly added."
I don't think so. This is telling me that you haven't properly restored the cooler.
Sorry, reality bites,
Just remember that not enough TIM - or too much TIM - can result in thermal issues. Also, it is actually possible to have a bad result if you tighten the heatsink down too much, if the board is not well supported underneath, etc. and etc. The rule I use is, if the temperatures are not good, start again! Also, make sure you properly clean both the processor and heatsink before you start (both surfaces should shine).
The first time I changed cpu I used the old paste. It was the same temp. Took it off and cleaned it very well. Same temp. This is a hp z620 workstation so it's well build.
Well, I will never be accused of using HP and "well built" in the same sentence (well, other than to say they don't belong together).
Have you tried putting the other processor back to see whether the problem still occurs with it? This would tell you if there is a possibility of, for example, the BIOS Configuration being incorrect.
Other than that, I cannot thing of anything else to try. If you want to request a RMA replacement, contact Intel Customer Support directly. Here is contact information by geography:
http://www.intel.com/content/www/us/en/support/contact-support.html# @11 Intel Customer Support Contact Information for US and Canada
http://www.intel.com/content/www/us/en/support/contact-support/emea-contact.html Intel Customer Support Contact Information for Europe, Middle East and Africa
http://www.intel.com/content/www/us/en/support/contact-support/apac-contact.html Intel Customer Support Contact Information for Asia-Pacific
http://www.intel.la/content/www/xl/es/support/contact-support/lar-contact.html Intel Customer Support Contact Information for Latin America
You can also try the chat service (available here: http://intelsupportchat.force.com/icslivechat/ics_tech_desktop_ww_english_Chat Intel Customer Support Chat Service), but this is English-only and subject to PST TZ business hours.