E8500 overheating

Hi all,
I'm building a new system, and it keeps shutting down a couple minutes after booting up due to the core getting too hot (108C or so then it auto-shuts down). It will overheat even when I'm just in the BIOS watching the core temp, where I can see it climb about 1C every second. I'm using the stock heat sink, defaults for all my BIOS settings, and all my fans are running. I've used both the thermal grease that comes with the heat sink, and cleaned it off with rubbing alcohol and tried putting on some myself (based on how it looked when I removed it I think I got a pretty nice thin film and a good contact), but it didn't effect the overheating at all. I've tried reseating the heat sink several times, each time it felt pretty solid, but again, it didn't help. Is it possible the chip is faulty in some manner and so it just running too hot?

Thanks a lot,
J

Sorry, here are the specs.

DFI LP DK X48-T2RSB PLUS LGA 775 Intel Motherboard
Intel Core 2 Duo E8500 Wolfdale 3.16GHz LGA 775 65W CPU
XFX PVT98WYDFH GeForce 9800 GTX+ 512MB GPU
4GB (4x1GB) G.SKILL DDR2 1066 RAM

No OS as of yet, but plan on installing WinXP once it stays on long enough to do so.

Push pin coolers can be tricky to install.
A bad installation can lead to higher temperatures, and even cpu throttling.
With the pc powered down, gently rock the cooler to see if it is on solid, or if it wobbles a bit.
Push pin coolers are best installed while the motherboard is outside of the case.
You need to be able to look at the back of the board to verify that
all 4 pins are completely through and locked.
Play with the pins on the cooler first, so you can see exactly how they work.
Read the instructions that came with your retail cpu.
When pushing down on the pins, do a diagonal pair first.
If you don't, it is hard to get the last pin in.
Don't forget to clean the parts and reapply fresh thermal compound every time.
Don't try to reuse the TIM.
Rubbing alcohol is OK as a cleaner.
I use a paper coffee filter to clean with because it is lint free.
Any name brand TIM should be OK(as-5, Mx-2, etc.)
When applying the TIM, don't use too much, because it can act as an insulator.
Don't apply too little, either, because it won't spread and fill the microscopic
imperfections in the surfaces. A dollop about the size of a grain
of rice should be about right.

Did you buy it from a small local business or a large chain? An unfortunate part of the CPU world is that small businesses will buy slower CPU's and overclock them to higher specs and resell them as a higher model to get the markup. You may have had that happen to you and stock cooling will never be enough. If you didn't... send it back... it's obviously faulty.