Strange noise

[njmudrat]

Very strange and very hard to describe.Like a tingy,pingy almost like when you pour cold water on a hot piece of metal and the truck was warmed up not hot.So strange and I heard backing out of my driveway.When the truck is on the side of my house I can hear the echo,other wise I never would of heard it.Like pop than nothing than another small popping pingy sound.lol....My check engine light is on and going to the dealer on tues.Thought maybe somebody here may have some insight