Built my first computer about 8 months ago after teaching myself everything about computers all my life. I, of course, built it extremely poorly. I had the stock fan on that was giving me good temperatures, 35C idle and 60C stress, but of course I decided to fix what wasn't broken and got a Cooler Master Hyper 212 EVO.
First time I installed it (about 6 or 7 months ago), I messed up badly, it was a messy job, my entire computer in general has poor cable management as is. And I got thermal paste everywhere. I was getting around 40-45C idle and still about 60C stress. It eventually started getting to 50-55C idle (like it is now) and around 60-65C stress.
Everything else looks fine, though, my GPU is 32C, my HDD is at 32C, and according to SpeedFan temp1 is 38C, temp2 is -55C, and temp3 is 45C (not sure what those mean, though). I have quite a few fans, and I'm pretty sure they're not all plugged in to where they can be read, just where they have power. They all are on from the looks of it.
Today, I got some new Arctic Silver thermal paste (instead of what came with the cooler master fan), and cleaned up my CPU/fan/heat sink and put everything on and it all looks pretty good and clean. The only thing I couldn't clean, was the thermal paste that's in my CPU socket (picture below) and there's very little still stuck around the edges of my CPU, as I said, I put it in very poorly last time. I couldn't get the paste out of the socket (I didn't notice the one in the middle until a friend pointed it out in the picture after I was done), so I just ignored it and hoped it would still work good.
But, an hour later I'm still getting the same poor temperatures of about 50-55C idle.
So, how do I clean my socket? Could that just be what's wrong? Or could just the heatsink or CPU itself be faulty? Maybe even the second time around I put too little thermal paste instead of too much. I went for about pea size in the middle.
Take the board out, put it on a desk or table and then get out a needle. Use the needle to slowly remove the compound away from any pins and be very careful. Will likely take 30min to an hour to do right. Don't try using a q-tip or cotton swab.
If it works I would leave it alone. Trying to clean thermal paste from in between the pins might lead to a bent pin which will make your motherboard a brick. You can try using a sewing needle but again you have to be very careful. As for your temperature problem I would wipe of the old thermal and make sure the heatsink is seated right and locked all the way down.