Complications of Motor Oil in a Diesel Fuel Tank

• Adding motor oil to your diesel fuel tank can have serious consequences.diesel image by Martina Berg from Fotolia.com
  
  Adding motor oil or other unproven diesel additives to your diesel fuel tank can result in inconvenient and expensive complications. Some drivers have added motor oil, believing that it will improve lubrication and help an engine run better. Diesel engines and fuel tanks, though, are only designed to take diesel fuel and some approved diesel additives.
  
  

Fuel Tank

• Depending on how much motor oil has been added, you may have to drain your fuel tank. The fuel tank should not be feeding the engine any motor oil mixed with diesel.
  
  

Injector Pumps

• The fuel injector pumps may become clogged. Motor oil is thicker than diesel, and the injectors are not designed to handle it. The greater the amount of motor oil you have added, the more likely that the injectors will become clogged and need to be replaced. Clogged injector pumps will result in the engine failing. Replacing fuel injectors can be very costly.
  
  

Clogged Fuel Filter

• A fuel filter filters out impurities from the fuel before it is fed through the injector pump. Some of the motor oil may pass through the filter, clogging the injectors. Whatever oil is blocked by the filter will likely also result in clogged fuel filters. The filters will need to be removed and cleaned. A clogged filter can result in delayed starting of the engine and the engine stopping.