Car has vvvvrrrrrrrrrrrrr sound when I first start accelerating?

Got my car back from having a head gasket job. Now when I first start accelerating from a stop, it makes a vrrrrrrrrrrrrrrrrr revving sound at about 5mph and then by 10 mph its gone and no further sounds but it does it every time I stop again and press the gas I hear it again. I had the shop who did the gasket job run a test drive, they really didn’t help or tell me anything just that its a older car and maybe its just making this sound, but its funny it didn’t do this before I got my gasket fixed. Any ideas? Did they do something else to my car?