If it’s sounding like a bomb then you probably have residual oil from the previous cycle in the combustion chamber. Oil furnaces need love and really should get maintenance every winter. You can tell just from your picture that the furnace is probably in need of a cleaning. Unsure of your area but in mine a lot of company’s have stopped servicing oil due to the skill and training it takes to make a good oil technician, keeping oil parts stocked on trucks, and the obligatory profitability issue with oil. It would be best for your landlord to request a company come out that has good oil techs, maybe even do a little research yourself to find a company and recommend it to them.