@Robin2: 80 can not be used as a marker; it indicates that the data relates to the motor; other codes are possible but OP is not interested in them. 81 is for a turbocharger, 82 for transmission and so on; any value from 0 to 255 is valid.
The message can contain multiple sets of information and each set has a specified length (as far as I could figure it out).
This, to me, looks like it needs data to be sent in bursts to be able to handle this format.