2008 V6

My temp gauge randomly drops to zero while driving, stays that way for a while, then comes back on and reads correct temp. Was happening infrequently. Recently it dropped full cold while driving, but I noticed the idle was faster. Then the gauge went back to normal and idle was normal. Then 10 minutes later it did it again. I shut off the engine and immediately restarted. The gauge stayed full cold and the car ran rough and popped and I thought it was going to stall. Ran like...

Temp gauge randomly drops to zero