During extreme cold or heat my car often makes a humming noise while I'm slowing or stopping. Sometimes it shuts off but when I'm able to and hit the gas the humming quits and the car continues to run fine. It never happens when I'm accelerating only when I'm rolling to a stop. I wonder if it is fuel related just because it always stops when I push on the gas. Any ideas??
The humming noise that you are describing may be your cooling fan kicking on, When you slow down the heat from your engine becomes stagnant raising the ambient temperature in your engine compartment. This fan kicks on to maintain that temperature, and will kick off when you accelerate due to moving air.
A. J. Valle