My temp guage shows hot when my car is not!

[Nate_M]

My temperature guage shows my car is running hot and my coolant level light is on and the coolant is full. I have had a vary small coolant leak for about 6 months but hedge only had to top of the coolant twice in that time frame. The guage is one notch away from the H. I left the engine ruining and took off the coolant cap and it bubbled a bit and was fine so i don't believe it's really ruining hot. My fans do run but the ac doesn't come on. If i turn on my heater it's working fine but the temp guage didn't budge.
Could this be a simple temperature sensor or coolant temp sensor bad or anything else? Please help my tech is backed up and can't get me in for 2 Weeks... 2001 A6 2.7L

[Vinnie981]

coolant temp sensor(easy fix) and or coolant level sensor that is built into the coolant resivor so you have to buy a whole new expansion tank.

[Nate_M]

coolant temp sensor(easy fix) and or coolant level sensor that is built into the coolant resivor so you have to buy a whole new expansion tank.

I changed the sensor but broke the clip that holds it in... the dealer is closed so i hope AutoZone has it...

[VAVAMATT]

I have same problem with the same car.... Changing temp sensor too...