Xserve 2.93Ghz fans running loud after SSD install and memory upgrade

Just upgraded the memory to 48gb and added SSD drive. Fans started running high at about 4k RPM. Replaced fan array and also reset SMC. Any ideas on how I can fix this?? I also downloaded a program that lets me reduce the fan speed. Reduced all to 2k RPM but fan 4 refuses to go below 4k.