Hi. Today after turning on my PC I started to crash after about 5 minutes even when idle. I tracked it down to my GFX suddenly overheating to 139 degrees with no GPU load! I took the card apart, cleaned the fan (including fins), took off the heatsink, cleaned off all the dried up and brittle compound and replaced it with a generous helping of Arctic Silver. When I power it up all has worked fine and haven't crashed since. After I powered up i was getting a reading of between 38-45 degrees, which is good for this particular card (it has always been hot). I have now noticed that my temperature is fluctuating between 176 and 48 degrees. This reading appears to be changing between these temps on every update, so cannot possibly be valid. I just had a moment when the card's fan kicked in full speed for a second and then go back to normal. I have tried three programs to monitor the temp and they all report this fluctuation. Is the sensor malfunctioning? Is it time to invest in something new? Screenshots taken less than a second apart: Note the GPU temp readings.