How to Check Transmission Fluid in a BMW

1. Park your BMW on a flat area. Start the car's engine and allow it to idle until it's warmed up. Check the temperature gauge to find out when the car is warm. If the BMW hasn't been driven for awhile, this could take several minutes.
2. Allow the car to idle. Raise the hood and find the transmission dipstick. It will be located toward the back of the engine compartment. It may be a different color than the motor oil dipstick. The transmission fluid dipstick may even have a picture or words on it. A telltale sign is that the tube the dipstick fits in is smaller than the motor oil tube.
3. Grab the top of the dipstick and pull it up and out of its tube. Wipe it off with the old rag. Then, replace the dipstick, making sure you push it all the way down.
4. Pull the dipstick out. Check to see how far up the fluid reached on the stick. (If you don't see any fluid at all, that means there is none.) If the fluid reaches the 'Full' mark, then you don't need to add any. If the transmission fluid reached below the full mark, you need to add enough to bring it up.