So the car is a 06 mini cooper s with a auto trans. So here is my issue it was long overdue for a fluid change at 90k miles so I bought 6quarts of fluid and started the process. After the first change it ran ok after the second change the next day it was banging into first and slipping third. I am thinking great I stirred something up. I changed it again and nothing changed. I noticed it was only taking 1.5 quarts per change when everyone say it should take 2 to 2.5. So I added a half quart and what do you know it shifts fine again. So heres the question what am I doing wrong because I really want to get an accurate amount of fluid in there.

This is the process I did. I drained it at 100f I removed the drain plug and the plastic piece. I then reinstalled the plastic piece and began to fill the trans with 100 degree fluid. I had the car as level as possible. At this point it took about 1.5 quarts. I then installed the fill plug started it put it in reverse for 2-5 seconds neutral for 2-5 drive for 2-5 then back to park. I then shut the car off remove the fill plug and start to fill again until it fluid comes out. It seems like all the fluid I add comes back out after a few minutes of filling. In other words if I slowly put in half a quart half a quart slowly drains back out. The entire time all fluid are kept over 90 degrees.


So what am I doing wrong that makes it so my trans will only take 1.5 quarts?

 

You have to make sure the car is level. and the temp of the transmission should be 95-133 degrees F. What you are experiencing right now is a transmission with not the correct amount of ATF in it. Are you checking it with the car running? That might be your problem! good luck!

 

Yeah the procedure I wrote is the procedure I did each time. I checked the fluid with the car off because you can't start it with the fill plug removed. Is checking it while its off correct?

 

Nope, the car should be running. Install the fill plug, start it and let fluid run out the drain plug with standpipe installed. You are underfilled because fluid drains to the pan when the car is off.

Also, you get more out if the car has been sitting a while for the same reason. Fluid drains when it is off. Some people let it drain over night to get the most out of it.

 

Thanks for the help guys. Unless I keep missing it pelican parts write up doesnt mention to leave the car running while checking the fluid. I am sure youre right though. Thanks

 

Yep.. I had a hunch you were checking the level with the car off. You always check it with it running! Good luck!