Popcorn noise wen come off a roundabout to go up a hill

[Andypyn]

Hi just wondering if everyone has an idea what might cause my 2015 a4 diesel make a popcorn noise for a few seconds then went a way not done it again been for good drive it did it wen I put my foot down to go up a hill arthter coming off a roundabout for a few seconds the car runs and sounds normal 

[Steve Q]

Was it like a backfire?