Wolfdale E8400 CO temps.

How about BIOS monitor? I would trust to realtemp, but that's high for a water-cooled system.

I'm 67.2 F ambient and my E8500 (C0) @ 4097MHz 1.28- 1.344v says 41- 42C idle, hits about 51C heavy load.
Idle temp dont mean shiat, run some ORTHOS for 20 min and see what your Load temp stabilize at.

It all depends on you WC set up and how many chips you have in your loop.
Post some specs on your loop please along with your clocks and voltages.

Bios reports 46-47C

Cpu 1.14v
FSB 1.19v

Stock 3.0 clock

core1 movement 7
core 2 movement 7

only the CPU in the WC loop (if thats what your asking)

its Alienwares water cooling, not sure what specs your looking for.

take pictures of it and post them. Alienware generally rebrands some of the equipment they put into their machines. It might be a kit.

Dust can kill any thermal transfer, clean that it out asap and post some results after =D

The E8400 I have also runs hot with water cooling. The temperature senders tend to not work correctly. Real Temp is the most accurate monitor for Intel CPU's. It is adjustable by adding a negative number when setting it up. Ideally the core temp should be around room temperature, but that's rare. It shouldn't be more than 10° C above room temperature with a decent system. A good system puts you 5° C above, an extremely good one at 2° C above. 60°F = 15°C. You may just have to guess & add a negative number to get a true ball park figure.

Yes, a clean computer is a happy computer.

Your sensors could be stuck. Idle temps don't mean a hill of beans with 45nm CPU's. Load it down like pixel said and check load temps. My bet is they don't increase all that much, meaning your set up is fine.

My E8400 runs high thirties idle and low fifties when loaded by Orthos
I am running @ 3.6ghz. with 1.30 Vcore your temps are not that bad.
On a side note my temps are reported in PC probe real temp shows them to be 10 degrees cooler but I do not worry to much about temps unless the go real high.

ran orthos for a bit and under load it was at 52-53C

Realtemp puts my C0 @ 56c during orthos small ffts.

4275mhz @ 1.51v