Based on the context and the answer, generate a question. 

Context: Anyway , my pop and uncle drained all the oil out and fixed Indy up right quickly . But now . I went to pick Indy up from the mechanic today ( the engine thing only got finished over the weekend ) and when I got there , there was a huge dent in the roof . Apparently Billy had the car parked on the street on Saturday and a branch fell on Indy .

Answer:

Because the car needed an oil change .



What 's a possible reason they drained all the oil out ?