Glow Plug sound

[Josh]

So sometimes when I turn the key to the "On" position while cold, the glow plug light comes on and I can hear a pretty loud buzzing sound.. Sometimes it comes back after I start the car too. Anyone know what that sound might be? Sounds like it is coming from the engine bay on the driver side near the firewall. Can the glow plug relay make that kind of sound? Doesn't sound very healthy.