rattle noise from the Motoraum FK2

When my FK2 is running on stand gas you can hear some noise when you are standing in front of the car. Kind of sounds like a plastic part close to the cooler. Thought first of all to the numberboard frame but there everything is fixed. Very strange. What is that now again? Probably the Englishmen have slumped again. Will be looking for me tomorrow at daylight times, otherwise it goes off to Hรคn dler, once again Has a touch of a diesel gruss