answer: #Person2#and Frank notice the strange noise coming from the motor due to lack of water. They decide to wait till it cools down.
documents: #Person1#: Frank, do you hear that strange noise?
  #Person2#: Yes, I have noticed it for a while. It seems to be coming from the motor.
  #Person1#: What shall we do?
  #Person2#: I don't know. Perhaps if we slow it down we can stop at the next park place and check what is the matter.
  #Person1#: OK, Let's do it.
  #Person2#: Oh, it is burning hot, We have run out of water.
  #Person1#: How is the motor itself? Is it OK?
  #Person2#: I think it's all right. Let's wait till it cools down a bit.