Burned Oil

• 1). Slide the transmission oil dipstick out from its tube.
  
  
• 2). Wipe the top of the dipstick with your index finger and thumb or a paper towel.
  
  
• 3). Inspect the oil. If it's dark brown or black, the oil is burned. Smell the oil to confirm burning. The oil is likely filled with friction material such as metal. This indicates friction with the band and clutch from slipping and overheating. Take your vehicle to a mechanic for inspection. The burning could be a major problem.
  
  

Varnished Oil

• 1). Inspect the internal components of your engine. If you see a light brown film, your transmission oil is likely varnished.
  
  
• 2). Inspect the tip of your oil dipstick. If you see a brown film there as well, you have confirmed that your oil is varnished.
  
  
• 3). Replace the oil immediately. You might be able to avoid costly repairs.
  
  
• 4). Inspect the thickness of the film. If it is a solid instead of a liquid, and it has been this way during freezing temperatures, your transmission might need to be rebuilt. When the film freezes, it could crack servos, pistons and hydraulic valves.